Concrete  Pavements, 

Sidewalks,  Curb 

and  Gutter 


PREPARED   BY   THE   INFORMATION   BUREAU 

UNIVERSAL  PORTLAND  CEMENT  CO. 


PUBLISHED  BY  THE 

Universal  Portland  Cement  Co, 

CHICAGO    —    PITTSBURGH    —    MINNEAPOLIS 


FIRST  EDITION.  1913 


INTRODUCTORY 

PROBABLY  no  divisions  of  concrete  construction 
are  more  closely  allied  than  Pavements,  Sidewalks, 
Curb  and  Gutter. 

In  addition  to  the  fact  that  all  are  often  laid  in 
close  proximity,  there  is  a  decided  similarity  in  ma- 
terials and  methods  of  construction.  Much  repetition 
can  be  saved  by  combining  the  points  common  to  all, 
as  has  been  done  in  the  first  part  of  this  booklet,  deal- 
ing later  more  specifically  with  each  type.  It  is  ob- 
vious, then,  that  the  first  section  should  be  studied, 
no  matter  which  of  the  three  constructions  the  reader 
is  particularly  interested  in. 

Illustrations  are  often  of  more  educational  value 
than  volumes  of  text,  and  failures  are  frequently  more 
beneficial  when  studied  than  examples  of  perfect  work, 
consequently  not  only  successes  but  typical  failures, 
will  be  discussed  with  the  hope  that  defective  work 
may  eventually  disappear. 


Copyright  1913 

UNIVERSAL  PORTLAND  CEMENT  CO. 
Chicago — Pitttburfh— Minneapolis 


Table  of  Contents 


Page 

Concrete  Pavements,  Sidewalks,  Curb  and  Gutter  (General  Discussion) 
Qualifications  for  Good  Paving  Material  .......  7 

Materials  for  Making  Concrete,,.        ........  8 

General  Construction  Details      .........  20 


Concrete  Pavement  Construction: 

Concrete  the  Most  Economical  Permanent  Pavement 

Material  and  Qualifications 

Equipment     . 

Types  of  pavement 

Preparation  of  Foundation 

Crown     .... 

Placing  Concrete  and  Reinforcing 

Table  of  Concrete  Pavements  placed  in  1911 

Pavement  calculations  and  examples 

Concrete  Sidewalk  Construction: 

Advantages  of  One-Course  Walk 
Preparation  of  Foundation  and  sub-grade 

Forms 

Recommended  Proportions 

Placing 

Cost 

Sidewalk  Calculations  . 

Curb  and  Gutter  Construction: 


Various  Types       .... 
Forms,  Materials,  Foundations,  etc 
Construction  of  Curb 
Construction  of  Curb  and  Gutter 
One-Course  Work 
Cost 


Commercial  Forms: 

Various  Types        .... 
Tampers,  long  handled  tools,  etc. 


Specifications : 

Pavement  . 
Sidewalks  . 
Curb  and  Curb  and  Gutter 


26 


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Concrete  Pavements,  Sidewalks, 
Curb  and  Gutter 


The  appreciation  and  need  for  highway  improvement  are  becoming 
keener  each  year.     An  increasing  and  progressive  population  demands 
the   most  advanced  and  best  adapted  construction  for  every 
meef»e*W          purpose.     Pedestrian  and  all  other  kinds  of  traffic  require  a 
requirements  comparatively  smooth  and  even  surface,  which  concrete,  in- 
telligently handled,  will  give.     For  minimum  traction  resist- 
ance, a  pavement  must  be  hard  and  rigid  enough  to   support  without 
change  of  form,  whatever  may  come  upon  it;  this  requirement  concrete 
also  fulfills. 

An  ideal  pavement,  whether  for  foot  or  other  traffic,  is  one  which 
will  remain  the  same  under  all  climatic  and  weather  conditions,  is  non- 
absorbent,  dustless,  easily  cleaned,  and  low  in  first  cost  and  mainte- 
nance. Concrete  measures  up  well  to  all  these  requirements,  and  ap- 
proaches closely  the  ideal  pavement. 

Nevertheless,  the  success  of  concrete  in  the  pavement  depends  not 
only  upon  knowledge  of  methods,  care  and  skill  in  manipulation,  but 
like  any  other  construction,  upon  the  selection  of  proper  and  durable 
materials. 


Figure  2 — Concrete  pavement  in  Kansas  City.  Missouri 

-7- 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 

Materials 

The  sand  and  gravel  found  in  different  sections  of  the  country  comes 
from  various  banks,  each  having  its  own  peculiar  grading  and  charac- 
teristics. The  crushed  stone  may  vary  in  hardness,  in  gradation,  or 
may  be  coated  with  dust  in  such  a  manner  as  to  make  it  unfit  for  use 
without  treatment;  consequently  the  aggregates  should  receive  careful 
thought  and  scrutiny  before  a  definite  selection  is  made. 

On  the  other  hand,  when  the  Portland  cement  comes  from  a  reputable 
manufacturer,  careful  inspection  is  not  advisable  unless  the  quantity 
of  work  will  justify  the  expense.  In  such  a  case,  confidence  should  only 
be  placed  in  laboratories  with  complete  and  standard  equipment. 

The  methods  for  testing,  adopted  by  the  American  Society  of  Civil 
Engineers,  January  20,  1904,  with  subsequent  amendments,  should  be 
used  and  the  cement  should  comply  with  the  Standard  Specifications 
for  Portland  Cement  of  the  American  Society  for  Testing  Materials, 
adopted  June,  1904,  together  with  subsequent  changes  and  amendments, 
or  the  Specifications  and  Methods  adopted  by  the  U.  S.  Government 
(Bureau  of  Standards,  Circular  No.  33). 

A  sack  of  cement  has  a  net  weight  of  94  pounds,  and  can  be  considered 
in  volume  as  equal  to  one  cubic  foot,  which  greatly  simplifies  propor- 
tioning. Different  brands  of  cement  give  slightly  different  shades  of 
color  in  the  concrete,  therefore  where  uniformity  of  color  is  desired, 
one  brand  of  cement  should  be  used  throughout  the  work. 
Aggregate  Concrete  is  no  stronger  than  its  aggregate.  It  makes  no 


igure  3 — Clean  materials  only,  are  suitable  for  concrete  construction.  Where  clean  aggregates 
are  not  obtainable,  some  means  must  be  provided  for  washing.  The  above  illustration  shows  one 
method  used  for  separating  sand  and  gravel,  washing  the  materials  at  the  same  time.  The  bank 
gravel  shown  in  the  left  background  is  shovelled  upon  the  slanting  screen  which  is  kept  flooded  by 
a  stream  of  water  drawn  by  a  centrifugal  pump  from  the  nearby  river.  In  the  foreground  is  shown 
the  gravel  pile,  and  at  the  right  the  sand  pile. 


Universal    Portland     Cement     Co. 


difference  how  well   the  cement  may  test,  if  the  gravel,  sand  or  stone 
does  not  possess  the  necessary  requisites,   the  job   will  be  a  failure. 
Good  appearing  sand  or  gravel  will  sometimes  develop  charac- 
*sel*ction      ^eristics   which   may   disfigure   and  even  destroy  the  work  into 
necessary     which  it  enters.      Quite  often,    shaly    pebbles    which    are   not 
noticeable  except  under  careful  scrutiny  will,  when  used  in  the 
concrete,  disintegrate,  and  in  so   doing    expand,     breaking    out   large 
pieces  of  top  mortar.    When  such  particles  occur  in  the  sand,  the  disin- 
tegration gives  the  whole  surface  a  pitted  appearance,  disfiguring  the 
work.  Clay  is  also  detrimental  when  occurring  as  a  coating  on  the  par- 
ticles, and  in  many  places    it   is    absolutely    necessary   to    provide   a 
washing  apparatus,  which  will  remove  it.     Many  installations  of  com- 
mercial types  of  washers  are  in  satisfactory  use.    However,  by  spreading 
the  material  out  on  a  loose  board  platform,  in  small  quantities  and 
turning  on  a  stream  from  a  %-inch  garden  hose,  very  satisfactory  results 
have  been  obtained.    When  the  job  is  not  too  large,  this  same  process 
can  be  applied  to  the  washing  of  sand.     The  apparatus  illustrated  in 
Figure  3    is  combined  so  as  to  wash  and  screen  in  the  same  operation . 
The  size  and  gradation  of  the  different  particles  as  well  as  the  clean- 
liness of  the  surfaces,  will  materially  affect  the  strength  of  the  concrete. 
The  size  of  the  sand  grains  has  a  decided  influence  upon  the  strength 
and  is  clearly  illustrated   by   the  following  diagram,  in  which 
size  of  sand  *ne  so^^  columns  represent  the   relative   areas    for  the   same 
grains  volume  of  spheres  of  different  sizes   (which  may  be  consider- 

ed as  sand  grains)  and  the  open  columns  represent  the  effect 
of  size  of  sand  grains  on  the  strength  of  cement-sand  mortar.  As  the 
making  of  a  first-class  concrete  necessitates  the  perfect  covering  of 
every  particle  of  sand  with  cement,  and  every  particle  of  the  coarser 


Relative    areas   for  the   -same     volume    of   spheres 
of    differenf     sices  ,     and    the    effect 

of    size     of     sand     grams  on 
£.  the  sfpengfh  of  morfor 


— 


SOUD     DIAGBAMS     RfPRESE NT     AREAS 
OPEN     DIAGRAMS    REPRESENT     -STRENGTH 


Figure 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 

aggregate  with  the  cement-sand  mortar,  it  is  apparent  that  materials 
with  an  excess  of  fine  particles  should  be  avoided.  The  same  line  of 
reasoning  is  applicable  to  the  combined  aggregate  in  the  concrete. 

It  does  not  necessarily  follow,  though,  that  because  coarse  particles 
have  the  smallest  area  per  unit  of  volume  that  the  aggregate  should 
all  be  large,  since  particles  of  the  same  size  have  a  large  amount  of  open 
Voids  sPace  between  and  consequently  require  a  maximum  of  cement 
to  fill  it  up.  The  open  spaces  between  the  particles  of  aggregate 
are  technically  called  "voids"  and  naturally  have  an  influence  upon  the 
amount  of  cement  required.  The  voids  in  sand  will  average  around  33 
per  cent,  while  in  stone  or  gravel,  the  open  space  averages  in  the  neigh- 
borhood of  45  per  cent.  In  proportioning  concrete  for  maximum 
strength  and  density,  it  is  necessary  to  use  more  cement  than  that 
actually  required  to  fill  the  voids  in  the  sand  and  more  mortar  than 
necessary  to  fill  the  stone  voids  exactly.  In  the  specifications  and 
recommendations  which  are  made  later  for  mixtures,  an  average  con- 
dition for  the  country  has  been  assumed  and  the  proportions  specified 
according  to  the  best  practice  for  the  type  of  construction  used. 

For  minimum  voids  and  the  best  concrete,  the  size  of  the  fine  aggre- 
gate should  grade  from  %  inch  in  the  largest  dimensions,  down  to  the 
finest,  with  the  coarser  particles  predominating,  and  in  no  case  should 
fine  aggregate  be  used,  of  which  more  than  four  per  cent  passes  through 
a  sieve  having  100  meshes  per  linear  inch.  • 

The  United  States  Geological  Survey,  Bulletin  No.  331,  Series  R, 
Structural  Materials  3,  has  furnished  some  very  valuable  data  on  the 
value  of  sands  and  limestone  screenings  found  throughout  the  United 
States,  which  should  be  studied  by  all  who  are  interested  in  this  im- 
portant subject.  The  results  show,  distinctly,  the  comparative  value 
of  sand  and  limestone  screenings,  which  vary  in  the  relative  proportions 
of  the  different  sized  grains,  as  well  as  the  quality  of  the  material. 


Comparative  Value  of  Sands 


Sam- 

Source 

Per 

Per 

*  %  Retained  on  Sieve 
No. 

Compressive 
Str.  at  1  Yr. 

A. 

her 

of 

Supply 

Location 

cent 
of 
Voids 

of 
Silt 

1:3  mortar 
in  Ibs.  per 
sq.  inch. 

10 

20 

30 

40 

50 

Thru 
50 

I 

Bank  Sand 

Attica,  Ind  

34.0 

3.9 

4.1 

10.3 

10.0 

19.0 

13.8 

30.0 

4475 

1 

Bank  Sand 

Attica,  Ind  

26.9 

0.7 

27.1 

20.9 

10.4 

14.3 

7.2 

7.3 

7750 

3 

River  Sand 

St.  Clair  River. 

40.5 

2.0 

1.0 

1.8 

2.0 

8.5 

25.3 

00.  0 

2729 

4 

River  Sand 

St.  Clair  River. 

29.7 

0.2 

39.5 

27.  5 

11.0 

9.4 

0.8 

4.7 

0742 

6 

Limestone 

St.  Louis,  Mo  . 

42.1 

10.1 

9.9 

40.3 

13.7 

7.9 

7.2 

31  .  0 

4908 

o 

Limestone 

Greenfield,  Ohio 

37..  5 

1.1 

44.4 

21.4 

8.5 

4.9 

3.4 

17.4 

8400 

The  sieve  number  refers  to  number  of  meshes  per  linear  inch. 

Comparing  Samples  1  and  2,  taken  from  the  same  bank  near  Attica, 
Indiana,  and  differing  only  in  size  of  grains,  it  will  be  noticed  that  when 
made  up  into  a  1 :3  mortar,  the  compressive  strength  of  sample  2  is 


Universal    Portland     C '  e  m  ent     Co. 


Sample  No.  3 


Figure  5— Showing  sands  of 
tars  made  from  them. 


2729  Ibs.  per  sq.  in. 
with  strengths  of  mcr- 


(The  sands  repre- 
sented by  Samples 
1  and  2  were 
screened  from  a 
gravel  of  glacial 
origin  at  Attica, 
Indiana.  This  ma- 
terial is  excavated 
by  steam  shovel, 
screened  into  sev- 
eral  sizes  and 
washed.  Samples  1 
and  2  illustrate 
very  clearly  the 
possible  variation 
in  sands  taken 
from  the  same  de- 
posit, and  also  in 
a  general  way  give 
a  fairly  correct  idea 
of  the  appearance 
of  a  well  graded 
sand.  From  the 
table  opposite  can 
be  obtained  the 
granulometric  an- 
alysis, together 
with  the  relative 
strength  under 
compression  when 
mixed  in  a  1  :  3 
mortar. 

The  sands  repre- 
sented by  Samples 
3  and  4  were  taken 
from  the  St.  Clair 
River  by  a  centri- 
fugal pump.  Since 
taken  from  the 
same  stream, 
their  composition 
and  general  char- 
acter, excepting 
size  of  particles, 
must  naturally  be 
quite  identical.  By 
reference  to  the 
table,  as  well  as 
the  illustrations,  it 
will  be  seen  that 


Concrete    P  are  merits ,     Sidewalks,     Curb    and    Gutter 


the  two  sands  are 
very  different  in 
granule  metric 
composition;  also 
that  the  compres- 
sive  strength  of  the 
two  sands  when 
made  up  into  a  1  :3 
mortar,  is  very 
much  in  favor  of 
the  coarser  sand. 

The  limestone 
screenings  repre- 
sented by  Sample  5 
were  taken  from  a 
crushing  plant  near 
St.  Louis.  Of  the 
crusher  run  ma- 
terial  50  per 
cent,  passed 
through  34-inch 
screen.  The  grad- 
ing of  the  screen- 
ings is  not  at  all 
uniform,  as  shown 
by  the  granulo- 
metric  analysis. 

Sample  6  was 
taken  from  a  crush- 
ing plant  at  Green- 
field, Ohio,  and 
represents  the 
screenings  separat- 
ed from  the  crusher 
run  material  by  %- 
inch  screen.  With 
the  exception  of  the 
largeamountoffine 
material  the  screen- 
ings are  very  well 
graded,  and  the 
strength  devel- 
oped when  mixed  in 
the  proportion  of 
1:3  is  very  much 
superior  to  that 
developed  by  Sam- 
ple 5,  when  mixed 
in  the  same  pro- 
portion.) 


ple  N 


8400  Ibs.  per  sq.  in. 


Figure  6 — Showing   sand    and    screenings   of  varying    coarseness  with 
strength  of  mortars  made  from  them. 

—12— 


Universal    Portland    Cement    Co. 


more  than  70  per  cent  greater  than  the  compressive  strength  of  Sample 
1.  As  other  conditions  are  the  same,  it  is  reasonable  to  conclude  that 
the  low  strength  shown  by  Sample  1  is  due  entirely  to  poor  gradation 
and  excess  of  fine  particles.  Like  conditions  prevail  with  Samples  3 
and  4  taken  from  the  St.  Clair  river,  near  Detroit,  Michigan.  Sample 
3  is  a  very  fine  sand,  60  per  cent  passing  the  50  mesh  sieve,  and  the  effect 
of  such  fine  material  is  readily  discernible  in  the  compressive  strength. 
Sample  4,  which  represents  a  well  graded  sand  from  the  same  stream, 
gives  a  compressive  strength  nearly  150  per  cent  greater  than  Sample  3. 

That  a  large  proportion  of  fine  particles  in  limestone  screenings  is 
detrimental,  is  shown  by  the  tests  on  Samples  5  and  6.  Here  also,  the 
compressive  strength  is  in  favor  of  the  coarser  material,  Sample  6  being 
more  than  70  per  cent  stronger  than  Sample  5. 

Especial  care  should  be  exercised  in  the  selection  of  limestone  screen- 
ings and  laboratory  results  should  not  always  be  taken  as  indicative  of 
the  same  action  in  the  field.  It  is  possible  through  careful  kneading 
and  mixing  in  the  laboratory  to  obtain  excellent  test  strengths 
Limestone  on  limestOne  screenings  containing  an  excessive  amount  of 
ungs  just.  However,  when  this  same  material  is  placed  in  the  mixer 
on  the  work,  it  has  a  tendency  to  ball  up  and  often  produces  a  very 
chalky  and  unsatisfactory  concrete.  Some  advance  the  theory,  in 
explaining  the  frequent  occurrence  of  poor  concrete  resulting  from  the 
use  of  limestone  screenings,  that  the  water  is  absorbed  from  the  concrete 
by  the  limestone  particles  subsequent  to  mixing,  causing  a  poor  surface 
bond. 

On  account  of  the  nature  of  the  material,  granite  rock  has  not  as 

much  tendency  to  dust,  under  crushing,  as  limestone,  and  so  in  general, 

presents  a  better  surface  for  the  cement.    An  additional  advan- 

Gramte       i&ge  [s  the  high  resistance  to  abrasion  which  is  especially  essen- 

nngs  j.-aj  jor  ^e  wearmg  surface,  and  any  material  used  in  a  surface 

having  heavy  wear,  should  be  hard  enough  to  scratch  glass. 

The  usual  commercial  granite  screenings  are  graded  in  size  from 
24-inch  down  to  the  finest  and  should  of  course  be  free  from  an  excessive 
amount  of  dust.  Sometimes,  screenings  can  only  be  obtained  in  wrhich 
the  particles  run  up  to  }/£-inch  in  largest  dimensions,  in  which  case 
screening  over  %-mch  screen  and  remixing  in  the  specified  proportions 
are  recommended. 

Coarse  Aggregate.  The  finer  aggregates  have  previously  played 
the  most  important  part  in  providing  suitable  and  durable  wearing 
surfaces,  and  until  lately  the  coarse  aggregates  were  used  only  in  the 
base  of  the  pavement,  and  were  never  exposed  to  the  wear  direct.  How- 
ever, with  the  introduction  and  general  adoption  of  single-course  work, 
the  importance  of  careful  selection  of  such  materials  is  further  increased. 

Good  gravel  can  be  obtained  in  almost  any  locality  and  its  existence 

often  determines  whether  the  one  or  two-course  pavement  is  specified 

Gravel      ^or  roadways.      Where  the  materials  must  be  shipped  in  for  the 

wearing  surface,  the  two-course  road  using  granite  screenings  in 

the  top  mortar  is  probably  the  most  economical.    The  gravel  should 

always  be  clean;  when  not  so,  washing  is  recommended.     The  largest 

dimension  will  be  determined  by  the  type  of  work  into  which  it  enters. 


('  DH  c  ret  e     P  a  r  e  in  e  n  t  ,v ,     Sidewalks,  'Curb    and    Gutter 


The  smallest  size  should  be  not  less  than  J^-inch;  in  other  words  the 

sand  should  be  separated  out  before  proportioning. 

Limestone  also  makes  a  satisfactory  coarse  aggregate  for  use  when 

it  does  not  take   the   wear   direct  as  in  a  sidewalk  or  pavement,    and 

mestone       ^s    ^ree   ^rom   dust.      If    covered    with    dust,   the    adhesion 
between  the  limestone  and  the  cement  mortar  is   interfered 

with.     Most  limestone  if  free  from  dust,  will  show  a  distinct  sparkle 

when  the  surface  is  ex- 
amined in  the  sun.  A 
chalky  surface  should 
be  sufficient  cause  for 
rejection,  since  it 
provides  nothing  to 
which  the  cement  may 
bond, and  a  poor  con- 
crete almost  always 
will  result  from  the 
use  of  materials  so 
coated.  In  size,  the 
limestone  should  vary 
from^-inch  up  to  \]/% 
inches  in  dimensions, 
but  such  can  rarely 
be  obtained  since  it  is 
the  practice  for  most 

quarries   to  furnish 

materials,    all    the 

pieces  of  which  are 

approximately  the 

same  size,  due  to  the 

different  sized  screens 

through    which    they 

have  passed.   In  such 

a  case  the  use  of  the 

1  ]/2-inch  stone  is  gen- 
erally   recommended. 
Crushed  granite 

usually  is  available  in 

the  same  sizes  as  the 

crushed   limestone, 

and  should  preferably 

be  graded  from    \}/% 

inches    down    to    % 

inch  in   dimension. 

It  is  preferred  to  the  limestone  because  of  its  hardness,  but  is  not 
Cranite    K(>ncrally  used  for  the  one-course  pavement  because  of  the  diffi- 
culty in  spreading,  the  angular  pieces  seeming  to  catch  under  the 

strike  board  and  pull   out  of  the   concrete   rather   than  work  in  like 

the  rounded  pieces  of  gravel.     When    used   in  the  wearing  surface  the 


possibilities 


Universal    Portland    Cement     Co. 


granite  is  specified  in  two  sizes,  the  one  from  ^  mcn  down  and  the  other 
from  ^  inch  to  J/2  mcn  m  dimension.  The  second  grade  helps  to  form  a 
durable  surface,  which  is,  of  course,  the  object  in  any  paving  material. 

The  service  which  a  concrete  pavement  gives,  depends  not  only  upon 
the  quality  of  the  materials  but  upon  the  proper  relation  between  the 
amounts  of  different  sizes.  Many  fail  to  appreciate  this  point  and 
consequently  build  pavements  using  the  bank  run  of  gravel 
Bank  without  any  'dea  of  the  gradation  and  distribution  of  the 
sizes  of  various  particles.  From  analyses  of  a  number  of  samples 
from  different  pits,  the  proportion  of  fine  to  coarse  material  has 
been  found  to  vary  greatly,  in  the  majority  of  instances  there  being 
an  excess  of  sand.  When  an  analysis  of  the  bank  run  shows  this  condition, 
it  is  often  possible  by  screening  and  remixing  in  the  proper  proportions 
to  add  more  coarse  material,  thereby  cheapening  the  construction  cost 
without  loss  in  strength.  Thus,  in  a  number  of  cases,  the  contractor 
will  be  repaid  for  the  extra  labor  required  for  screening  bank  gravel 
both  in  cement  saved  as  well  as  in  the  satisfaction  that  his  work  has  been 
constructed  uniformly — a  requirement  especially  necessary  in  road 
improvement. 

The  illustration,  Figure  8,  shows  plainly  the  different  strata  in  a 
gravel  pit.  It  is  clear  that  such  a  pit  will  give  gravel  of  varying  qual- 


Figure  8 — Showing  the  various  strata  and  variation  in  che  averag?  sand  bank.  In  order  to  pro- 
vide against  loam  in  aggregate  coming  from  such  a  bank,  thorough  washing  or  else  stripping  to 
the  base  of  the  dark  streaks  is  necessary. 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 

ities,  depending  upon  what  proportion  of  the  different  layers  is  included, 
as  well  as  what  section  of  the  bank  the  material  is  taken  from.  By 
screening,  a  practically  uniform  sand  and  gravel  are  assured.  The 
darker  streak,  which  can  be  seen  along  the  upper  edge  of  the  bank,  and 
extending  down  through  the  strata,  shows  black  loam,  which  is  often 
the  cause  of  trouble  in  concrete  construction.  In  the  majority  of 
instances,  the  loam  occurs  only  on  the  surface  above  the  gravel,  and  can 
be  removed  by  stripping.  In  this  case,  even  though  the  top  layer 
were  removed,  trouble  would  still  be  experienced  from  the  leads  which 
are  carried  down  and  through  the  bank,  emphasizing  the  need  for  a 
thorough  investigation  of  the  materials  to  be  used  in  concrete. 

Water.  Oftentimes  it  is  necessary  to  look  further  than  the  gravel 
bank  to  locate  the  cause  of  poor  work,  and  many  times  the  quality  of 
water  used  in  the  mixing  contributes  toward  unsatisfactory  concrete. 
The  tendency  to  use  water  from  pools  or  stagnant  ponds,  because  of  a 
slight  saving  in  labor  and  equipment,  should  be  discouraged  and  only 
clean  water  of  a  quality  fit  for  drinking  purposes  should  be  used. 

Sub-Base  Materials.  Although  water  is  a  necessary  material  in 
mixing  concrete,  its  presence  under  the  finished  pavement  is  liable  to 
cause  trouble  unless  some  means  is  provided  for  caring  for  it.  If  the 
soil  has  naturally  good  drainage,  no  further  provision  is  necessary;  if 
not,  a  sub-base  is  essential  and  should  be  composed  of  a  material  which 
will  remain  porous  indefinitely.  For  this  purpose  steam  cinders,  gravel, 
crushed  stone,  slag  or  other  durable  materials  are  recommended.  Broken 
brick  have  been  suggested,  but  should  not  be  used  unless  hard  burned, 
because  of  their  tendency  to  disintegrate  from  frost  action. 


accd  on  grades  as  high  as  18%. 


Universal    Portland    Cement     Co. 


Colorings.  The  use  of  coloring  matter  in  roadways,  sidewalks, 
curb  and  gutter,  is  becoming  more  general  every  year,  because  of  the 
realization  that  the  reflected  glare  from  a  white  or  nearly  white  surface 
is  annoying  and  the  feeling  that  it  is  injurious  to  the  eyes  is  growing. 
Some  sidewalk  specifications  provide  for  the  coloring  of  all  sidewalk 
surfaces.  The  coloring  matter  commonly  used  is  lampblack  or  iron 
oxide.  Any  mineral  coloring  may  be  used  if  the  quantity  required  to 
give  the  desired  shade  does  not  exceed  ten  per  cent  of  the  weight  of  the 
cement.  Lampblack  is  permanent  while  some  of  the  other  colors  have 
at  times  given  trouble  from  fading  after  being  placed  in  the  work. 
The  following  paragraph  and  table  are  taken  from  "Cements  and 
Concrete"  by  *Louis  C.  Sabin,  and  contain  suggestions  which  will  be 
of  value  where  coloring  wTork  is  contemplated: 

"The  dry  mineral  colors  mixed  in  proportions  of  2  to  10%  of 
the  cement  gives  shades  approaching  the  color  used.  Bright 
colors  are  difficult  to  obtain  and  would  not  be  in  keeping  with  a 
masonry  structure  except  in  architecture.  When  mixed  with  an 
American  Portland  cement  mortar  containing  one  part  cement  to 
two  parts  by  weight  of  a  yellow  river  sand,  the  particles  of  which 
are  largely  quartz,  the  colors  indicated  in  the  following  table 
were  obtained:" 

"With  no  coloring  matter  added,  the  mortar  was  a  light  greenish 
slate  when  dry.  Ultramarine  green,  in  amounts  up  to  8  per  cent 
of  the  cement,  had  no  apparent  effect  on  the  color  of  this  mortar. 
Variations  in  character  of  cement  and  sand  will  affect  the  result 
obtained  in  using  coloring  matter.  The  colors  indicated  below 

*Gen.  Supt.,  St.  Mary's  Falls  Canal,  Sault  Ste.  Marie,  Michigan,  Member  Amer.  Soc.  of  C.  E. 


Figure  10 — Placing  concrete  pavement  at  Mason  City,  Iowa. 

—17— 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 


are  for  dry  mortar.  When  the  mortar  is  wet,  the  shades  are 
usually  darker.  None  of  the  materials  mentioned  in  the  tables 
seems  to  affect  the  early  hardening  of  the  mortar,  though  very 
much  larger  proportions  might  prove  injurious." 

Colored  Mortars 

Colors  Given  to  Portland  Cement  Mortars  Containing  Two  Parts 
River  Sand  to  One  Cement 


Dry 
Material 
Used 

Weight  of  Dry  Coloring  matter  to  100  Lbs.  Cement. 

Cost  of  Col- 
oring mat- 
ter per  Ib. 
(cents). 

H  Pound 

1  Pound 

2  Pounds 

4  Pounds 

Lamp  Black  .  . 

Light  Slate.  .  .  . 

Light  Gray  

Blue  Gray  

Dark  Blue 
Slate  

15 

Prussian  Blue. 

Ultramarine 
Blue  

Yellow  Ochre. 
Burnt  Umber 

Light  Green 
Slate  

Light  Green.  .  . 

Light  Pinkish 
Slate  

Light  Blue 
Slate  

Light  Blue 
Slate  

Pinkish  Slate.. 

Blue  Slate  .... 
Blue  Slate  

Bright  Blue 
Slate. 

50 

20 
3 

10 

Bright  Blue 
Slate  

Light  Buff  
Chocolate  

Dull  Lavender 
Pink  

Venetian  Red. 

Slate,  Pink 
Tinge  

Bright  Pinkish 
Slate  

Light  Dull 
Pink  

Dull  Pink  

VA 

Chattanooga 
Iron  Ore..  .  . 

Light  Pinkish 
Slate  

Dull  Pink  

Light  Terra 
Cotta  

Light  Brick 
Red  

2 

Red  Iron  Ore 

Pinkish  Slate  .  . 

Dull  Pink  

Terra  Cotta... 

Light  Brick 
Red  

VA 

A  very  slight  difference  in  the  amount  of  coloring  used,  will  cause 

variations  in  the  shade  of  the  finished  work;  consequently,  all  materials 

must   be   measured   accurately.      Some   writers   suggest 

Accurate measur-  that  enougn  top  be  mixed  for  the  entire  job,  so  as  to 

ing  of  color  mate-    .  .,.  ,  -i  i          i 

rials  necessary  insure  uniformity  but  this  is  not  always  possible  where 
the  work  is  of  large  size.  If  the  coloring  matter,  cement 
and  sand  are  very  carefully  weighed  out  or  measured  for  each  batch, 
and  the  coloring  mixed  with  the  cement  before  the  sand  is  added;  then 
the  coloring,  cement  and  sand  uniformly  mixed  dry  before  adding  the 
water,  the  result  should  always  be  uniform  and  satisfactory. 

Collecting  Sacks.  While  the  careful  collecting  and  care  of  cloth 
cement  sacks  has  nothing  to  do  with  the  quality  of  concrete  construc- 
tion, they  are  details  which  should  be  looked  to  with  care  by  the  con- 
tractor who  wishes  to  keep  costs  at  the  minimum.  With  cement  at 
$1.50  per  barrel,  the  value  of  a  cloth  sack  is  over  25%  of  the  value  of 
the  cement  contained  in  it,  and  yet  through  carelessness  in  handling, 
many  are  hopelessly  torn,  thereby  losing  cement,  as  well  as  the  sack. 
Care  should  be  exercised  also  in  preventing  the  sacks  from  becoming 
wet  since  the  cement  hardening  in  the  cloth  fibre  makes  the  sacks  worth- 
less for  refilling.  After  emptying,  the  sacks  should  be  spread  in  piles 


•  U niversal    Portland    Cement     Co. 


along  the  work,  collected,  counted  and  bundled  every  day.  Such  a 
system  will  materially  cut  down  costs,  not  only  in  labor  but  by  keeping 
the  sacks  in  better  condition. 

Expansion  Joint  Filler.  For  filling  expansion  and  contraction 
joints,  asphalt,  paving  pitch,  or  tar  is  recommended  which  will  compress 
before  allowing  the  pavement  to  heave.  The  poured  fillers  must  have 
two  essential  characteristics.  To  be  satisfactory,  they  must  remain 
ductile  under  the  range  of  temperature  to  which  subjected,  and  under 
no  conditions  become  sticky.  Felt  is  also  used  satisfactorily  for  this 
purpose.  Care  should  be  exercised  to  see  that  the  material  for  the 
expansion  joints  is  so  placed  that  it  will  prevent  any  foreign  matter 
from  lodging  in  the  joint  after  being  in  place  and  thus  destroy  its  value. 

Expansion  Joint  Protection.  In  sidewalks  and  curb  and  gutter 
construction,  the  ordinary  half-inch  rounded  corner  is  sufficient  protec- 
tion. In  roadways,  the  wear  and  impact  are  much  greater,  making 
some  other  treatment  desirable.  A  2  inch  x  2  inch  angle  properly  anch 
ored  makes  a  very  satisfactory  protection  for  the  concrete  but  the  anchors 
must  be  firmly  attached,  so  as  to  prevent  any  motion  of  the  angle  after 
being  placed.  Special  shapes,  consisting  of  a  plate  curved  to  fit  the 
street  crown  with  portions  punched  out  for  the  anchor,  are  manufactured 
by  the  R.  D.  Baker  Company,  Detroit,  Michigan. 


Pain  re  U     Placing  a  two-course  driveway  with  metal  forms. 

—19- 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 

Construction 

Preparation  of  Sub-Grade.  Conditions  throughout  the  country 
are  so  variable  that  it  is  manifestly  impossible  to  lay  down  any  set  of 
rules  which  will  be  applicable  in  every  section.  Where  the  soil  is  sandy, 
no  sub-base  is  necessary,  while  in  other  soils,  the  neglect  of  a  proper 
sub-base  might  result  disastrously.  The  necessity  of  the  sub-base  must, 
therefore,  be  left  to  the  discretion  of  the  builder  or  the  successful  practice 
in  the  cunimunity.  If  the  soil  at  the  excavated  grade  is  firm  and  solid, 
there  is  no  necessity  for  further  preparation,  but  if  any  soft  or  spongy 
places  are  disclosed,  they  should  be  removed  and  the  holes  filled  with 
firm  material  packed  solidly.  When  the  sub-grade  occurs  on  fills,  its 
preparation  requires  extra  care,  since  many  failures  can  be  traced  to 
this  cause.  The  different  parts  should  be  tamped  in  layers  not  to  exceed 
6  inches  in  thickness.  Wherever  available,  the  intelligent  use  of  water 
will  assist  materially  in  compacting  the  fill. 

Drains.  If  water  accumulates  in  the  sub-grade  there  is  danger  of 
upheaval  from  frost.  In  soil  where  the  sub-base  and  natural  drainage 
cannot  take  care  of  the  water,  some  other  means  must  be  provided. 
The  best  method  of  supplying  additional  drainage  depends  upon  the 
available  outlets,  etc.  In  some  places  a  broken  stone  trench  suffices, 
while  in  other  localities  a  tile  drain  is  necessary.  Well  made  tile  are 
recommended  for  this  purpose;  for  sidewalks,  the  4- inch  size  is  gener- 
ally adequate,  but  smaller  sizes  should  not  be  used,  as  they  fill  up  with 
mud  and  clog  the  drain. 


Figure  12 — By  means  of  a  boom  and  bottom  dump  bucket,  a  large  area  can    be   covered  without 
shifting  the  position  of  the  engine  and  mixing  machine. 


Universal    Portland    Cement     Co. 


Measuring  of  Materials.  Upon  uniformity  of  measurements 
depends  the  success  of  concrete  construction.  Even  though  the  speci- 
fied proportions  are  correct,  if  variation  in  the  relative  amounts  of 
materials  takes  place  the  pavement  will  have  merit  only  in  proportion 
to  the  quality  of  the  poorest  sections.  Consequently,  it  is  necessary 
that  after  the  proportions  are  fixed,  means  be  provided  for  insuring 


Figure  13 — Four-foot  measuring  box.     Every  3  inches  in 
height  represents  a  volume  of  one  cubic  foot. 

unvaried  adherence  throughout  the  work.  Particular  attention  should 
be  directed  toward  insuring  uniform  loading  of  wheelbarrows.  The 
exact  proportions  can  generally  be  attained  by  striking  off  the  material 
with  a  straight  edge  or  template.  If  the  barrows  cannot  be  struck  off 
to  the  even  proportion,  the  use  of  a  bottomless  measuring  box  of  known 
volume  is  recommended  to  obtain  the  exact  quantities  required.  A 
sack  of  cement  weighing  94  pounds  net  should  be  considered  as  one 
cubic  foot,  and  all  batches  should  be  mixed  in  multiples  of  an  entire 
sack. 

Mixing.  The  amount  of  material  which  should  be  mixed  at  one 
time  depends  upon  the  facilities  for  placing  the  concrete  when  mixed. 
Not  more  than  thirty  minutes  should  be  allowed  to  elapse  between  the 
time  of  mixing  and  the  time  of  placing.  The  thoroughness  of  mixing 
should  never  vary,  however,  no  difference  what  the  size  of  the  gang  or 
the  type  of  mixer. 

For  hand  mixing  of  concrete,  a  watertight  platform  is  recommended, 

on  which  is  first  spread  the  sand,  and  then  the  required  amount  of  cement. 

Two  laborers,  one  on  each  side,  should  systematically  turn  the  cement 

.  .       into  the  sand,  with  a  slight  "flip"  on  leaving  the  shovel, 

"ng  being  sure  to  cut  to  the  bottom  of  the  pile  at  each  stroke. 

This  operation  will  have  moved  the  location  of  the  pile  about  two  feet. 

Reversing  the  direction  of  the  operation  brings  the  pile  to  its  original 

position,  but  in  a  mixed  condition.     If  of  uniform  color,  the  required 

amount  of  gravel  or  stone  may  be  distributed  over  the  pile.* 

Two  more  turnings  should  thoroughly  mix  in  the  coarse  material 

*By  cutting  into  the  pile  with  a  shovel,  an  idea  of  the  uniformity  of  mixing  can  easily  be  obtained. 
The  appearance  of  streaks  indicates  the  need  for  another  turning. 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 


Figure    14 — Horse     dra 
from  the  mixer. 


dump-cart    for    distributing    concrete 


and  should  make  the  mixture  ready  for  the  water,  which  should  be 
added  in  the  form  of  a  spray,  while  the  laborers  are  turning  over  the 
pile,  as  described  for  mixing  the  sand  and  cement.  The  water  should 
never  be  added  faster  than  it  can  be  taken  up  by  the  materials.  As 
the  mixing  progresses,  it  will  be  noted  that  the  mass  becomes  more 
plastic  and  appears  wetter.  Water  should  not  be  substituted  for 
thorough  mixing. 

It  is  customary  to 
mix  mortar  by  hand  in 
the  usual  mortar- 

Mixing  b°X'  n°  <Jif; 
mortar  ference  what 
process  is  em- 
ployed for  the  con- 
crete, since  where  only 
one  machine  mixer  is 
provided,  it  is  imprac- 
ticable to  keep  shift- 
ing from  mortar  to 
concrete  and  vice 
versa.  Providing  two 
mixers  would,  of 
course,  eliminate  the 
need  for  the  mortar-box. 

Recent  experiments  conducted  on  the  strength  of  machine  concrete 

mixed  for  varying  periods  indicate  that  the  materials  must  remain  in 

.-    ,  .         .  .      agitation  with  the  water  for  at  least  a  full  minute.     The 

"ng  tendency   to   rush   the   work   is  not   productive   of  good 

concrete,   and   should   consequently   be   curbed.      In   general,   machine 

mixing  where  carefully  controlled  is  superior  to  hand  work,  since  fatigue 

of  the  workmen  has  no  influence  upon  the  thoroughness  of  mixing. 

Consistency.     Generally  speaking,   wet  concrete  will  give  better 

results  than  dry,  and  where  possible,  should  be  used.     In  sidewalk  and 

curb  and  gutter  work,  enough  water  should  be  used  so  that  it  will  just 

flush  to  the  top  under  light  tamping.     For  roadway  construction,  a 

similar  concrete  is  generally  used  for  the  two-course  work,  but  for  the 

single-course  construction,  a  wetter  mixture  serves  the  the  purpose  better. 

For  the  mortar  top,  a  medium  or  plastic  consistency  is  recommended. 

A  "soupy"  mixture,  sometimes  used,  is  luible  to  produce  a  poorly  bonded 

..  top,  and  besides  causing  very  slow  hardening,  has  a  bad  effect 

upon  the  cement  itself.    On  the  other  hand,  a  dry  mixture  finishes 

poorly  and  is  liable  to  show  blotches.    A  correct  mixture  will  just  show 

water  on  top,  after  being  "rodded"  off  several  times  with  the  straight 

edge  or  template. 

Placing.  With  the  sub-grade  or  sub-base  properly  prepared  and 
with  good  materials  correctly  proportioned  and  thoroughly  mixed,  the 
assembling  of  these  in  a  manner  which  will  result  in  a  permanent  structure 
should  not  be  neglected.  The  concrete  should  be  deposited  and  tamped 
into  final  position  within  the  forms  on  the  sub-grade  or  sub-base,  pre- 
viously wet,  as  quickly  as  possible.  On  hot  drying  days,  the  concrete 

—22— 


Universal    Portland    Cement     Co. 


should  not  be  permitted  to  stand  after  the  mixing  is  completed,  but 
should  be  placed  immediately,  even  though  it  necessitates  mixing  smaller 
batches. 

Any  perceptible  drying  of  the  concrete,  either  before  or  after  placing, 
is  apt  to  result  in  defective  work.  No  appreciable  time  should  be  allowed 
to  elapse  between  the  time  of  placing  of  the  mortar  and  concrete  since 
any  hardening  of  one  or  the  other  before  brought  into  contact  will  prevent 
a  good  bond. 

Expansion  Joints.  The  expansion  of  concrete  is  practically  the 
same  as  that  of  steel  .0000055  per  unit  length  per  degree  Fahrenheit. 
Thus  assuming  a  temperature  range  of  100°  and  a  pavement  100  feet  of 
length,  the  expansion  would  be  in  inches: 

100  x  100  x  12  x  .0000055   =  .66" 

This  figure  is  often  increased  in  actual  practice,  due  to  the  incompressi- 
bility  of  the  joint  filler  and  the  unintentional  introduction  of  foreign 
material,  either  at  the  time  of  or  subsequent  to  the  construction.  There- 
fore it  is  customary  to  provide  an  expansion  joint  every  25  feet  in  road- 
ways; every  50  feet  in  sidewalks  and  about  150  feet  in  curb,  and  combined 
curb  and  gutter,  the  range  of  temperature  not  being  considered  so  great 
in  the  latter  case,  because  of  the  less  surface  exposed.  A  satisfactory 
expansion  joint  should  have  perpendicular  surfaces  and  the  wedges 
used  for  this  purpose  should  be  tapered  only  slightly,  since  the  effective 
joint  is  measured  at  the  narrowest  portion  and  the  width  at  the  surface 
should  not  be  greater  than  necessary. 

Conditions  Governing  Color.  The  shade  of  the  finished  work 
will  vary  with  the  consistency  of  the  mixture,  the  amount  of  troweling, 
the  character  of  the  finishing  tool  used,  the  time  which  elapses  between 
placing  and  finishing  the  top,  and  with  weather  conditions  and  temper- 
ature; also  with  the  treatment  and  protection  the  work  receives  during 
the  first  48  hours  after  it  is  completed.  Of  course,  weather  and  temper- 
ature conditions  are  beyond  the  builder's  control,  but  he  should  make 
allowance  for  these  and  conduct  his  work  accordingly. 

It  is  not  unusual  to  see  a  surface,  which  has  been  finished  either  in  the 
late  fall  or  spring,  of  two  different  shades,  according  to  whether  it  was  in 
the  sunshine  or  shadow.  Work  affected  in  this  manner  usually  bleaches 
out  right  in  time,  but  until  this  occurs,  the  appearance  of  the  surface  is 
not  pleasing.  The  lack  of  uniformity  of  shade  or  color  in  the  same  work 
is  much  more  noticeable  than  the  lack  of  uniformity  of  shade  or  color  in 
abutting  sections.  .Therefore,  in  all  construction  an  effort  should  be  made 
to  produce  uniformity  in  color  throughout. 

It  has  probably  been  noticed  by  every  builder  that  a  steel  trowel 

gives  a  darker  finish  than  a  wooden  trowel  or  float,  and  that  a  dry  mixture 

gives  a  darker  finish  than  a  wet  one,  and  that  if  the  top  is 

finish™         allowed  to  become  too  dry  after  being  floated,  and  then  finished 

with  a  steel  trowel,  it  is  apt  to  contain  blotches  which  remain 

indefinitely.     Probably  all  who  are  interested  in  sidewalk  construction 

have  noticed  that  the  opposite  sides  of  a  stretch  of  walk  will  frequently 

appear  to  be  of  different  shades,  as  the  result  of  one-half  being  finished 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 


Steel  Trowel 


from  one  side,  and  the  other  half  from  the  opposite  side.      This  indi- 
cates clearly  how  very  sensitive  a  mortar  finish  is  to  varied  treatment. 

Protection  of  Work.  The  quality  of  the  finished  work  is  often 
just  as  dependent  on  the  protection  accorded  as  the  care  in  construction. 
On  particularly  hot  days  the  action  of  the  sun  and  air  causes  hair  cracks 
in  the  surface  and  in  some  cases  so  dries  out  the  water  that  proper  hard- 
ening is  impossible. 

Cold  weather,  too,  has  its  bad  effects.  Freezing  or  frost  may  destroy 
the  concrete  or  scale  the  wearing  surface.  The  scaling,  however,  so  mars 
the  work  as  to  make  relaying  frequently  necessary.  A  precaution  in 
cold  weather  which  should  not  be  neglected 
is  the  use  of  heated  water  and  aggregate. 
As  the  rate  of  hardening  is  influenced  by 
the  consistency  it  is  advisable  to  use  less 
water  when  the  temperature  approaches 
the  freezing  point.  The  use  of  warm  mate- 
rials will  greatly  accelerate  the  hardening  of 
the  concrete,  thus  developing  more  rapidly  a 
condition  which  makes  the  work  capable  of 
resisting  frost  action.  Even  though  heated 
materials  are  used,  the  surface  covering 
should  not  be  neglected,  for  by  failure  to 
protect  the  surface,  the  heat  in  the  walk 
is  rapidly  radiated  and  the  surface  is  then 
exposed  to  the  frost  action. 

Tools.      The  most  common  tools  used 
Steel         in    pavement    construction   are  the 
trowel       steej  trowei  an(j  Wooden  float.    Some 
finishers  prefer  cork  to  wood  for  floating. 

The  groover  or  jointer  is  the  tool  used 
for  dividing  off  different   sections   of   the 
work  for  the  benefit  of  appearance, 

as  we^  as  to  Prov^e  a  sure  division 

between  the  top  coating  of  adjoining 
work,  so  that  if  any  settlement  occurs 
the  crack  will  come  at  the  division  line. 
Consequently,  the  depth  of  the  point  should 
be  at  least  equal  to  the  thickness  of  the  top 
coating.  A  groover  giving  a  narrow  deep 
groove  is  the  best  for  sidewalks,  as  this 
prevents  excessive  wear  at  the  joints  from 
roller  skates. 

The  edger  used  for  finishing  off  the  work 
against  the  forms  may  be  considered  as 
half  a  groover,  but  with  a  larger  radius,  a 
}/2  or  ^4  inch  radius  being  the  most  com- 
mon size.  Where  the  work  turns  very  sharp 
corners  the  ordinary  edger  will  not  conform 
to  the  turns  and  another  tool  has  been 


Wooden  or  Cork  Float 


Edeer 


Groover 


Figure  15— Concrete  Finishing 

Tools 


Universal    Portland    Cement    Co. 


Short  Radius  Edger 


Curb  Rounder 


provided  called  a  "radius  tool,"  in  reality 

a  shortened  edger.  For  curb  and  gutter  work 

in  forming  the  face  corner  of  the  curb  an 

edger  of  lj/2  inch  radius  is  required,  while 

the   outer  edge   of  the   gutter  should   be 

finished  with  a  radius  of  only  about  ^  inch. 

After  the  face  form  is  removed  from 

Curb         the  curb,  the  edge  should  be  finished 

rounder    with  a  "curb  rounder"  and  where 

there  is  a  gutter  the  corner  should  be 

finished  out  writh  a  '  gutter  rounder." 

The  final  finishing  of  the  curb  can  best 
be    done   with    a  wide  fibre  brush.     This 

r.,      ,       ,    same  tvpe  of  brush  is  also  used 
riore  brush  «j          11        u    *.    *j.    *  11 

on  sidewalks,  but  it  is  generally 

possible  to  obtain  an  ideal  rough  finish  on 
a  plain  surface  by  simply  troweling  with 
the  wooden  or  cork  float. 

The  tamper  can  either  be  made  of  wood 
or  steel,  the  former  material  generally  being 
used  in  the  shape  of  a  round  log  or 
square  6x6.  Where  any  amount  of 
work  is  to  be  done,  the  steel  tamp  is  the 
most  economical.  Where  desired,  a  spe- 
cially shaped  tamper  may  be  used  which 
will  force  the  coarse  aggregate  away  from 
the  surface,  leaving  a  layer  of  mortar  which 
can  be  finished  with  the  trowel.  Various 
forms  of  this  tamper  are  to  be  found,  all 
accomplishing  about  the  same  purpose  but 
particularly  adapted  to  one-course  work. 


Tamper 


Gutter  Rounder 


Steel  Tamper  Special  Surfacing  Tamper 

Figure  16 — Concrete  Finishing  Tools 
—25— 


Concrete     P  a  r  e  m  e  n  f  s  ,     Sidewalks,     Curb    and    Gutter 


Concrete  Pavement  Construction 

History  teaches  that  commercial  centers  grow  and  prosper  in  pro- 
portion to  the  excellence  of  their  transportation  facilities.  A  good 
pavement  materially  increases  the  efficiency  of  a  public  highway  and  is 
probably  one  of  the  most  important  improvements  a  community  can 
undertake. 

The  various  types  of  pavements  now  in  general  use  are  the  result 
of  a  determined  effort  on  the  part  of  engineers  and  road  builders  to 
produce  a  durable  surface  for  public  highways  and  streets 
that  wil1  afford  the  least  resistance  to  the  modern  vehicle. 
The  search  for  the  ideal  low  cost  permanent  pavement  has 
led  to  the  use  of  practically  all  the  materials  of  construction,  but  as 
yet  no  one  type  of  pavement  has  been  developed  that  is  adapted  to  all 
classes  of  traffic  or  suitable  under  all  conditions,  and  a  pavement  that 
is  most  acceptable  in  one  respect  is  frequently  the  most  objectionable 
when  considered  from  another  point  of  view. 

Within  the  past  few  years  a  comparatively  sudden  change  in  traffic 
conditions  from  the  horse  drawn  vehicle  to  the  automobile  has  completely 
revolutionized  paving  construction.     Several  types  of  pavement 
which  were  formerly  accepted  as  suitable  for  the  improvement 


important  country  highways,  moderately  traveled  city  streets 


Traffic 

anges 

and  parkways,  have  proved  short-lived  and  unsatisfactory  under  the 

new  conditions. 

Larger  loads  In  order  to  economize,  the  farmer  must  haul  larger  loads 

must  be  carried  than  heretofore  and  must  have,  not  only    a    road    giving 


Fi6urt  17— Self  dumping  auto  truck:  capacity  4  cu.  yds. 

—26— 


Universal     Portland     Cement     Co, 


365  days'  service  each  year  but  one  which  will  cut  down  so  far  as  pos- 
sible the  tractive  effort  required  to  pull  the  load. 

Experiments  have  demonstrated  that  the  farmer's  team  can  haul 
five  times  as  much  load  over  a  concrete  road  as  over  a  clay  road.  In 
addition,  the  benefits  of  the  concrete  road  immediately  increase  the 
value  of  the  adjoining  land  an  amount  far  in  excess  of  the  assessment 
for  the  road  construction.  It  is  not  to  be  wondered  then,  that  the  intro- 
duction of  a  concrete  roadway  into  a  rural  community  has  invariably 
brought  numerous  requests  from  farmers  in  the  vicinity  for  extensions 
of  the  improvement. 

The  time  has  passed  when  the  sale  of  automobiles  was  confined  to 

the  cities.     The  farmer  now  owns  his  machine  and  is  consequently  as 

appreciative  of  a  good  road  as  the  tourist.     Many  farmers  are 

Farmers      delivering  milk  to  the  creamery  by  auto  and  the  practice  of 

'owners  °    handling   produce   and   supplies   in   large  quantities   by   motor 

trucks  is  rapidly  increasing.     Because  of  the  efficiency  of  this 

method,  it  seems  reasonable  to  believe  that  the  custom  will  become 

quite  common. 

The  present  tendency  of  some  road  authorities  to  place  restrictions 
on  the  allowable  loads  to  be  carried  should  be  discouraged  since  the 
efficiency  of  the  auto  truck  depends  upon  its  high  carrying 
Should  n  t    caPac^y   more   often   than   upon   the   speed   attained.      It   is 
be  reduced    ^ar  better  to  construct  a  pavement  which  will  meet  the  demands 
of  the  traffic    than  to  limit   the   loads  to  suit  the    roadways, 
and  no  economical  pavement  has  yet  been  developed  which  so  satis- 
factorily meets  these  demands  as  concrete. 


Figure  18 — A  novel  method  of  hauling  materials  is  here  shown  where  a  small  engine,  dump  cars,  and 
narrow  gauge  railway  parallel  the  line  of  construction  and  run  to  the  pit  from  which  the  gravel 
and  sand  are  obtained. 

—27— 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 


Up  to  the  year  1912,  over  5,000,000  square  yards 

5,000,000  square  yards  of   concrete   pavement  were  constructed  throughout 
^SfSlXS^     the    United    States,    which,    in    itself,    is    sufficient 

evidence  of  its  good  qualities. 

Concrete  pavement  has  been  in  satisfactory  use  for  a  number  of 
years.  Bellefontaine,  Ohio,  has  four  blocks  laid  in  1893  and  1894  which 
today  show  no  appreciable  wear  except  at  the  longitudinal  joints  which, 
according  to  present  good  practice,  never  should  have  been  placed 
in  the  pavement.  In  the  heart  of  the  business  district  of  Chicago  at  the 
warehouse  of  the  American  Steel  &  Wire  Company,  is  a  small  area  of 
concrete  pavement  laid  in  1903  which  has  been  subjected  to  exceptionally 
heavy  traffic  and  is  today  in  first-class  condition.  Detroit,  Michigan, 
has  one-half  block  of  concrete  pavement  laid  14  years  ago  and  LeMars, 
Iowa,  a  pavement  laid  in  1904,  both  giving  splendid  satisfaction.  These 
and  many  other  examples  serve  as  an  index  of  the  durability  and  wearing 
qualities  of  this  type  of  construction. 

Recently  a  committee  appointed  to  select  a  type  of  pavement  best 
adapted  to  the  requirements  of  Sioux  Falls,  South  Dakota,  considered 
seven  points — noise,  durability,  up-keep,  cleanliness,  sanita- 
tion'  adaPtability  to  rubber  tires,  and  cost.     The  accom- 
cortcrete  panying  table  shows  the  value  the  committee  placed  upon 

the  different  pavement  materials. 


Noise 

Dur- 
ability 

Up-keep 

Cleanli- 
ness 

Sanita- 
tion 

Adapt- 
ability 
to  rubber 
Tires 

Cost 
per  yard. 

Ideal  Pavement  

0 

10 

0 

10 

10 

10 

Minimum 

Granite  Blocks  

10 

10 

1 

1 

1 

1 

$4.50 

Brick  

8 

8 

3 

2 

4 

3 

2.25 

Concrete  (jasperite)    .  . 

5 

8 

3 

10 

10 

10 

1.35 

Asphalt  

4 

4 

10 

8 

8 

8 

1.75 

Sarco  

2 

4 

8 

8 

6 

8 

1.90 

Creosote  Blocks  

2 

6 

5 

6 

5 

6 

2.65 

No  rating  was  given  upon  the  ease  of  tearing  up  concrete  as  compared 
with  other  pavements,  but  this  point  has  been  covered  by  work  at  Fond 
du  Lac,  Wisconsin,  under  the  direction  of  City  Engineer  J.  S.  McCullough 
and  the  Superintendent  of  Construction  of  the  Wisconsin  Telephone  Co. 
It  became  necessary  to  tear  up  about  4,600  lineal  feet  of  concrete  pave- 
ment, and  200  lineal  feet  of  brick  street,  for  the  purpose  of  placing  tele- 
phone conduit.  Not  only  was  the  work  accomplished  satisfactorily, 
there  being  practically  no  signs  of  the  repair,  but  the  comparative  cost 
was  very  much  in  favor  of  the  concrete,  which  amounted  to  $1.83  per 
square  yard,  as  against  $2.27  for  replacing  the  brick  pavement.  How- 
ever, so  much  emphasis  should  not  be  placed  upon  the  flexibility  of  a 
pavement  as  upon  legislation,  which  will  compel  the  placing  of  conduits, 
sewers,  mains,  etc.,  before  the  pavement  is  laid.  Simply  because  the 
property  is  vacant  is  no  excuse  for  not  providing  adequate  facilities  for 
future  growth,  since  the  added  expense  for  tearing  up  and  replacing  the 
pavement  will  more  than  compensate  for  the  early  investment. 


Universal    Portland    Cement     Co. 


To  test  the  relative  abrasive  qualities  of  different  types  of  pavement 
material,  J.  C.  McCabe,  City  Inspector  of  Detroit,  Michigan,  designed 
a  machine  which  would  give  as  nearly  as  possible  an  imita- 
tion  of  traffic  wear-     The  machine  is  illustrated  in  Figure 
quality  ^  an(^  consists  of  two  large  and  weighted  metal  wheels, 

one  on  each  end  of  a  shaft,  which  revolves  from  a  central 
pivot  around  a  circle  paved  with  the  kinds  of  material  to  be  tested.  Each 
wheel  is  equipped  with  five  metal  plates  with  regulation  steel  horseshoe 
caulks  so  that  as  the  wheels  revolve,  the  caulks  strike  the  surface  of  the 
pavement  in  much  the  same  manner  as  does  a  horse's  hoof.  Thus  the 
weighted  wheels  correspond  to  the  tires  of  a  vehicle  and  the  caulks  to  the 
tread  of  horses. 

In  the  first  experiment  with  the  machine,  it  was  run  at  a  comparatively 
high  speed  to  give  a  severe  test  and  the  pavement  that  stood  up  the  best 
under  this  punishment  wras  the  1  :  1  %  '•  3  concrete  laid  under  the  speci- 
fications of  the  Wayne  County  Road  Commissioners.  The  wear  on  the 
surface  was  hardly  perceptible. 

Some  pavements  and  paving  materials  deteriorate  with  age,  and  where 

travel  is  light  go  to  pieces  due  solely  to  weathering,  long  before  they  could 

possibly  have  been  worn  out  by  traffic.     Concrete,  on  the 

Concrete  only    otner  hand,  when  properly  laid,  becomes  harder,  stronger  and 

ar0**      *      more  durable  with  age,  and  can  only  be  destroyed  by  the 

slow  process  of  wear  from  traffic.     When  compared  in  cost 

with  other  pavements,  concrete  without  doubt,  is  the  cheapest  permanent 


Figure  19 — Paying  "Determinator"  used   at    Det 

different  paving  materials.     The  wheels  and  caulks  give  a  very  close  imitation  of  actual  pavement 
wear  and  have  demonstrated  conclusively  the  superiority  of  the  concrete  pavement. 


Concrete    Pavements,     Sidewalks,     Curb    and    Glitter 


pavement  obtainable  for  most  localities,  The  variation  in  cost  of  the 
different  types  of  pavements  is  due,  for  the  most  part  to  the  character  of 
the  wearing  surface,  as  the  same  concrete  base  and  the  same  amount  of 
grading  and  drainage  will  answer  in  practically  all  cases.  With  some 
types  of  construction,  approximately  75  per  cent  of  the  cost  of  the  pave- 
ment is  for  materials  and  labor  in  the  wearing  surface  alone. 

The  concrete  pa  ve- 
ment  on  the  other 
hand  is  at  one  time 

Concrete 

pavement  keeps 

money  in  the 

community          wearing 

taxed  surface, 

and  possesses  the  ad- 
ditional advantage 
that  the  materials  for 
its  construction,  other 
than  the  cement,  can 
usually  be  obtained 
locally,  thus  keeping 
a  very  large  part  of 
the  cost  of  improve- 
ment in  the  commun- 
ity taxed.  Low  cost  of  materials,  small  requirements  as  to  equipment 
and  the  simplicity  of  construction  explain  the  low  cost  of  concrete 
pavement  as  compared  with  other  types.  In  addition  to  low  cost  and 
durability,  concrete  pavements  are  easily  and  economically  cleaned  and 
repaired,  and  from  a  sanitary  and  aesthetic  point  of  view  are  ideal. 

Materials.  Like  every  other  construction,  the  success  of  concrete 
pavement  depends  upon  the  quality  of  materials  used.  Day  by  day  the 
tendency  toward  closer  scrutiny  of  the  aggregates  is  becoming  more  marked 
in  all  concrete  construction  and  especially  is  careful  inspection  necessary 


Figure  20 — Road  material  in  place  along  the  line  of  the  proposed 
pavement.  The  materials  should  be  so  distributed  as  to  be  used  up 
in  the  same  ratio  as  the  road  progresses. 


Figure  21— Wagons  being 


Universal    Portland    Cement    Co. 


where  the  concrete  is  subjected  to  impact  and  abrasion,  as  in  the  roadway. 

Too  great  emphasis  cannot  be  placed  upon  the  need  not  only  for 
proper  proportioning,  but  suitable  materials.  Frequently  concrete  roads 
are  being  constructed  with  materia  s  entirely  unsuited  for  use  wrhen 
good  aggregates  could  be  obtained  at  slightly  greater  expense,  which 
in  the  end  would  pay  many  times  over  for  the  additional  outlay. 
Wherever  any  question  arises  as  to  the  advisability  of  different  sands, 
gravels  or  stones,  the  service  of  the  Universal  Information  Bureau  should 
be  sought  and  analyses  and  recommendations  will  be  furnished  free  by 
engineers  having  wide  experience  in  concrete  road  construction. 

Equipment.  Although  the  materials,  with  the  exception  of  cement, 
can  generally  be  obtained  in  the  neighborhood  of  the  proposed  work, 
special  equipment  is  necessary  in  addition  to  that  ordinarily  required  for 


•••^^••••••••••••Bl 

Figure  23 — General  layout  of  concreting  plant  for  building  concrete  roads 

—31— 


Concrete    P  avements ,     Sidewalks,     Curb    and    Gutter 

the  preparation  of  the  sub-grade  or  foundation  for  all  types  of  pavements. 
The  mixer  should  preferably  be  of  the  batch  type  provided  with  traction 
drive,  swinging  boom  and  bucket,  or  some  other  means  by  which  the 
concrete  can  be  deposited  in  place  with  minimum  handling. 

To  obtain  an  even  surface,  the  side  forms  should  be  made  of  steel  or 

2-inch  lumber  without  warp,  since  from  these  the  crown  and  grades  are 

,,  obtained  by  means  of  the  strike  boards.     The  wear  upon  the  upper 

edge  of  the  wooden  form  from  continued  use  is  considerable,  and 

the  addition  of  a  2x2  angle  will  lengthen  the  life  of  the  forms  indefinitely. 

Where  the  expansion  joints  are  placed  every  25  feet,  the  forms  and  angles 

can  be  cut  into  12^-foot  lengths,  but  in  attaching,  the  angles  should  be 

allowed  to  extend  three  or  four  inches  at  one  end,  and  fall  short  an  equal 

amount  at  the  other  end  of  the  board.     Thus,  in  setting  up,  a  lap  is 

provided  which  gives  a  good  joint  between  adjacent  forms. 

When  the  forms  are  stiffened  by  angles,  warping  out  of  shape  is 

eliminated,  which  decreases  the  labor  of  staking  and  number  of  stakes 

_      .       ,       required.     Steel  stakes  are  best  for  this  purpose,  and  since  in 

country   highway   construction  the   forms   are    removed  soon 

after  placing    the   concrete,    a    large    outlay    of    such    stakes    is   not 

necessary. 

To  obtain  the  proper  contour,  a  strike  board  is  required  which  is  cut 
to  the  proper  shape  and  protected  with  a  heavy  steel  strip  which  is 


Figure  24 — Near  view  of  curved   strike  board   for   giving  the  crown  to  the  pavement 
concrete  bucket,  mixer,  boom  and  steel  expansion  joint  in  place. 

-32— 


lowing  also 


Universal    Portland    Cement    Co. 


Finishing 
bridge 


turned  around  at  the  ends  to  form  handles  as  illustrated  in  Figure  24. 

ex  -L    L.       j    To  give  stiffness  and  protection,  a  steel  strip  is  also  fastened 
Strike  board       i  .1  j  /\  -.    •  .• 

along  the  upper  edge.   On  narrow  roadways,  it  is  sometimes 

the  practice  to  use  a  special  tamper  made  of  the  same  pattern  as  the 
strike  board,  but  with  a  ten-inch  face.  By  raising  the  tamper  up  and 
letting  it  fall  on  the  fresh  concrete,  the  pavement  is  given  its  first  finishing, 
as  well  as  driving  down  any  large  stones  into  the  concrete.  Such  a 
tamper  is  illustrated  in  Figure  23. 

Figure   23  also  il- 
lustrates the  finishing 
bridge   recommended 
for  narrow 
streets  and 
highways. 

This  is  constructed 
of  a  plank  with  steel 
underbracing  to  form 
a  simple  truss.  For 
wider  streets  a  long 
plank  can  be  used, 
carrying  the  braces 
up  through  the  plank 
and  connecting  above. 

Figure  25— Materials  being  hauled  to  the  work  by  traction  engine,        Rollers      Call      be      at- 
over  unimproved  roadway.  ,       ,  , 

tached    at    the    ends 

to  roll  either  on  the  side  forms  or  upon  planks  placed  along  the 
work.  The  bridges  with  underbracing  have  the  disadvantage  of  keeping 
the  finishers  at  some  distance  from  the  pavement  surface  on  the  wider 
streets.  This  trouble  is  not  encountered  when  the  bridge  illustrated  in 


Figure  26 — Roughen  Steel  Finishing  Bridge  in  use  at  Fond  du  Lac,  Wisconsin. 

—33— 


Traction 


Concrete    P  avements,     Sidewalks,     Curb    and    Gutter 

Figure  26  is  used.      P.    Roughen   of  Fond  du  Lac,  Wisconsin,  is  the 
designer  of  this  bridge  which  is  constructed  throughout  of  steel. 

The  building  of  roads  is  a  special  kind  of  concrete  construction  and 
the  equipment  must  be  fitted  to  the  purpose  in  order  to  reduce  costs  to 
a  minimum.     Where  the  construction  is  large,  where  long  hauls 
are  necessary,  or  in  districts  where  men  and  teams  are  scarce, 
hauling  materials  by  traction  engines  has  been  found  to  be  the 
most  economical. 

Concrete  road  construction  requires  an  enormous  quantity  of  water 
which  is  used  for  the  engines,  mixing  and. sprinkling.  In  some  cases, 
the  amount  exceeds  15,000  gallons  per  day,  which  makes  hauling  out 
Pum  s  °^  *ne  cluesti°n-  A  pump  equipment  and  a  two-inch  pipe  line 
can  be  installed  similar  to  that  illustrated  in  Figure  27  which 
will  deliver  water  for  several  miles.  Taps  can  be  placed  along  the  line 
every  200-300  feet,  to  which  a  hose  can  be  attached  for  the  construction 
work  and  subsequent  sprinkling.  The  proper  sprinkling  of  the  pavement 
is  just  as  necessary  as  care  in  construction  and  too  much  emphasis 
cannot  be  placed  on  equipment  which  makes  this  work  easy  of  accom- 
plishment. In  case  the  distance  over  which  the  water  must  be  forced 
is  too  great  to  maintain  the  needed  pressure  at  the  end  of  the  pipe,  a 
tank  should  be  provided  into  which  the  first  pump  can  deliver  the  water, 
using  a  secondary  pump  to  relay  it  on  to  the  work.  The  power  required 
to  operate  the  pumps  will  depend  upon  the  head  to  be  pumped  against, 
as  well  as  the  size  of  the  pipe  line.  On  level  country  a  4  H.  P.  gasoline 
engine  has  been  found  to  furnish  ample  power  for  pumping  water  a 
distance  up  to  three  miles  to  the  construction  gang,  and  for  sprinkling 
as  well. 


Figure  27 — Pumping  arrangement  for    furnishing  water  to  be  used 
protecting  the  work  by  sprinkling  subsequent  to  placing. 


the  concrete  and 


Universal    Portland     Cement    Co. 


Types  of  Pavements.  There  are  in  general  two  types  of  concrete 
pavement,  viz:  one-course  and  two-course,  which  may  further  be  sub- 
divided into  the  plain  and  reinforced.  By  the  one-course  work  is  meant 
that  the  pavement  is  all  composed  of  a  rich  concrete,  using  the  same 
proportions  throughout.  In  the  two-course  pavement,  the  base  con- 
sists of  a  slightly  leaner  concrete  than  would  be  used  throughout  the 
single  course,  but  the  top  consists  of  a  1:1 2^  mixture  of  cement  and 
granite,  or  some  other  tough  and  hard  aggregate. 

Which  type  of  pavement  is  best   depends    entirely  upon  the  local 

conditions  on  the  work.     Where  the  aggregates  to   be  found  in  the 

vicinity  are  not  suited  for  the  wearing  surface,  and  suitable  material 

must    be    shipped    in,   the  two-course  pavement  is  probably 

JWiic/i  type  a(ivisable  because  cheaper,  the  expensive  materials  being  used 

only  in  the  wearing  surface.     Such  marked  success  is  being 

reported  with  the  one-course  pavement   that   wherever  the  materials 

are  available,  this  type  is  to  be  recommended. 

Steel  reinforcement  is  used  in  wide  streets  to  strengthen  the  pavement. 
The  one-course  pavement,  placed  at  one  operation,  is  the  simplest  type 
of  construction,  but  with  the  introduction  of  reinforcement  comes  the 
need  for  two  operations  in  placing,  making  the  labor  of  placing  the 
concrete  about  the  same  for  either  the  one  or  two-course  work. 

Foundation.     An  important  part  of  a  concrete  road  is  the  sub- 
grade  or  foundation  upon  which  the  concrete  is  to  be  placed.     This 
should  be  brought  to  a  firm,  unyielding  surface  at  all  places  by  compacting 
with  a  ten-ton  roller.      Unequal  settlement  in  the  foundation 
Thorough      js  ajmost  sure  ^o  be  accompanied  by  unsightly  if  not  injurious 
compacting  ,       •       ,-,  r.  , ,         ..  ^  •         •  i  »• 

necessary       cracks  in  the  pavement.     All  soft,  spongy  or  yielding  spots 

should  be  removed  and  the  spaces  refilled  with  suitable  ma- 
terials, special  precautions  being  taken  in  refilling  these  spaces  and  in 
back  filling  the  trenches,  for  it  must  be  remembered  that  an  increased 
thickness  of  concrete  placed  in  or  above  an  improperly  refilled  hole  or 
trench  adds  nothing  to  the  stability  or  bearing  power  of  such  a  surface. 
Improperly  refilled  trenches  and  unsatisfactory  foundations  are  account- 
able for  many  cracks  in  concrete  pavements. 


Figure  28 — Preparing  the  sub-grade. 


Concrete    Pavements,     S  i  d  e  ic  alks ,     Curb    and    Gutter 

Special  attention  should  be  paid  to  drainage,  as  water  must  be  kept 

from  reaching  the  foundation.     On  highways  this  is  accomplished  by 

_     .  means   of  open  ditches  or  tile  drains  provided   with  suitable 

nage     outlets  or  as  indicated  in  Figure  1.      On   city  streets,  surface 

water  can  be  handled  at  catch  basins  connected  with  the  sewer  system. 

In  a  majority  of  cases  the  concrete  can  be  laid  directly  upon  a  prop- 
erly prepared  sub-grade,  but  in  exceptional  cases  a  sub-base  of  from  4 
inches  to   6   inches  of  gravel,   broken  stone  or  other  suitable 
Sub-base     materials  should  be  used.     After  grading  and  rolling,  the  sub- 
"ub-grade   grade  should  be  checked  and  accepted  by  the  engineer  in  charge 
before  depositing  any  materials  upon  it.     If  the  aggregates  are 
hauled  and  delivered  upon  the  proper  sub-grade,  it  should  again  be 
accepted  by  the  engineer  before  laying  the  concrete. 

Crown.  The  proper  crown  for  a  concrete  pavement  is  a  detail  of 
construction  that  has  not  been  given  sufficient  consideration,  and  the 
section  usually  adopted  has  been  practically  the  same  as  for  other  types 
of  pavement.  This  is  a  mistake,  since  a  high  crown  is  provided  mainly 
to  improve  the  drainage,  and  as  the  concrete  pavement  is  ideal  in 
this  respect,  a  crown  of  6  to  8  inches  sometimes  used  in  narrow  streets 
is  entirely  unnecessary.  The  height  of  crown  should  be  governed  by 
the  width  and  grade  of  the  street;  for  the  concrete  pavement  a  crown 
of  l-100th  the  width  is  ample. 

For  country  highways  and  narrow  city  streets,  the  pavement  should 

preferably  be  laid  upon  a  flat  sub-grade,  and  the  crown  obtained  by 

Flat  or        increasing  the  thickness  of  the  concrete  from  the  edges  towards 

crowned      the  center,  rather  than  by  laying  a  pavement  of  uniform  thick- 

sub-grade   ness  on  a  crowned  sub-grade.     The  flat  sub-grade  construction 

requires  but  little  additional  material  and  greatly  increases  the  strength 

of  the  pavement  at  the  center  where  it  receives  the  maximum  wear  and 

needs  to  be  the  strongest.     On  wide  streets,  where  reinforcing  is  used, 

part  of  the  crown  may  be  obtained  by  increasing  the  thickness  of  the 

concrete  and  part  by  crowning  the  sub-grade  as  described  in  Figure  1. 

Concreting. 
With  the  sub -grade 
prepared  and  the 

~       .  .  forms 

(Consistency  <        «     . 

staked    in 

position,  the  mixing 
of  the  concrete  can  be 
started.  Care  should 
be  exercised  that 
neither  too  much  nor 
too  little  water  is 
added  to  the  concrete, 
a  happy  medium 
being  obtained  in  the 
"quaky"  mixture.  Be- 
cause of  the  ease  in 
placing,  a  wetter  mix- 

f  °  i  .  ,    •         •  Figure  29—  Showing  travelling  bucket  dumping  charge  of  concrete. 


Universal    Portland    C  ement    Co. 


sometimes  used,  but  this  practice  should  be  discouraged  since  too  much 
\vater  injures  the  strength  of  the  concrete.  The  material  for  the  wearing 
surface  in  two-course  pavement  construction  should  be  mixed  wet  enough 
so  that  it  will  easily  spread  into  place  with  a  strike  board  or  template, 
but  not  so  wet  as  to  cause  the  separation  of  the  materials  or  an  excess  of 
water  on  the  surface. 

The  concrete  should  be  placed  in  strips  extending  across  the  full 
width  of  the  area  paved.  Concrete  for  the  base  in  two-course  work 

p.  .  should  be  tamped  to  a  grade  the  thickness  of  the  wearing  course 
g  below  the  finished  surface  of  the  pavement.  The  laying  of  the 
wearing  course  should  follow  closely  behind  the  laying  of  the  base,  and 
in  no  case  should  more  than  50  minutes  elapse  between  the  mixing  of  the 
concrete  for  the  base  and  the  covering  of  it  with  the  wearing  course.  In 
laying  the  single-course  pavement,  the  operation  consists  simply  of  filling 
the  forms,  striking  off  with  a  template  and  tamping  to  the  finished  grade. 

The  pavement  should  be  concreted  in  sections  between  expansion 
joints,  and  each  section  should  be  completed  as  a  unit,  without  stopping 
work.  If  the  concreting  has  only  progressed  through  part  of  a  section, 
the  abandonment  of  work  for  an  hour  will  be  sure  to  cause  cracking  at 
this  point,  after  the  pavement  is  exposed  to  traffic.  The  requirement 
may  sometimes  be  found  difficult  to  fulfill,  because  of  the  laborers  desiring 
to  stop  work  at  a  definite  time.  To  guard  against  troubles  of  this  kind, 
some  contractors  hire  men  with  the  understanding  that  work  is  to 
cease  when  the  foreman  decides. 

.,  .          .  The  determination  of  the  use  of  reinforcement  will  depend 

~ing  upon  the  type  of  foundation  and  width  of  pavement.    Reinforce- 
ment may  be  used  in  either  single  or  two-course  work,  and  is  particularly 


Figure  30 — Placing  a  metal  expansion  joint  in  concrete  street  pavement  showing  triangular  mesh 
reinforcing.  In  the  picture  are  shown  the  clamps  for  tightening  up  the  tar  paper  between  the  metal, 
as  well  as  the  smaller  fasteners.  The  large  clamps  are  removed  as  soon  as  the  concrete  is  placed 
around  the  joint.  The  smaller  clamps  are  removed  by  the  finishers  when  trowelling  the  surface. 


Concrete    Pare  merits ,     Sidewalks,     Curb    and    Gutter 

designed  to  care  for  slight  settlements  in  foundations,  and  to  guard  against 
contraction,  internal  stress,  and  to  give  the  necessary  strength  where 
the  pavement  is  wide.  Where  the  pavement  is  not  over  20  feet 
wide,  reinforcing  is  hardly  necessary,  but  for  widths  greater  than  20 
feet  the  need  for  reinforcement  is  generally  acknowledged.  In  any  road 
where  a  fill  of  over  two  feet  is  made  and  the  material  used  for  the  pur- 
pose is  other  than  sand  or  gravel,  the  pavement  should  be  reinforced,  no 
matter  what  the  width  of  the  road.  No  amount  of  compacting  by  roller, 
or  puddling  can  effectively  settle  such  a  fill  so  that  no  further  movement 
of  the  foundation  is  probable  after  the  placing  of  the  pavement. 

One  condition  that  often  arises  in  towns  or  cities  is  the  laying  of  a 

sewer  down  the  middle  or  side  of  the  street,  prior  to  placing  the  roadway. 

Where  such  excavation  is  necessary,  and  the  pavement  is  laid 

Special  upon  the  fresh  fill,  sufficient  reinforcement  should  be  placed 

~tng  near  the  base  of  the  pavement,  to  cause  it  to  act  as  a  beam  and 
thus  to  carry  the  load  over  to  the  more  solid  earth.  The  type  of  rein- 
forcement which  is  most  economical  in  price  and  handling  is  the  wire 
fabric.  The  size  and  weight  of  material  used  in  this  fabric  must  be 
determined  to  suit  each  specific  case. 

Finishing.  After  the  pavement  has  been  brought  to  the  required 
section  and  crown,  the  surface  of  the  concrete  should  be  finished  with  a 
wood  float.  This  will  reduce  the  air  and  water  pockets  and  produce  a 


Figure  31 — Concrete  is  not  fool-proof  and  with  improper  methods  of  handling  and  placing,  poor 
roadways  like  poor  sidewalks,  may  be  constructed.  The  above  illustrates  this  very  clearly  where 
inefficient  handling  and  placing  combined  with  lean  mixtures  and  dirty  materials  caused  unsatis- 
factory results. 


Universal     Portland     Cement 


denser  and  better  wearing  surface  than  that  left  by  the  strike  board, 
template  or  tamper. 

Where  the  roads  do  not  abut  a  curb  or  gutter,  the  edges  should  be 
bevelled  for  protection  as  well  as  to  prevent  the  formation  of  a  rut  from 
vehicles  turning  out  upon  the  shoulders.     The  easiest  method  of 
Bevelling  providing  this  bevel  is  by  removing  the  side  forms  while  the 


edges 


concrete  is  still  plastic  and  tamping  down  the  edge  with  the  back 


of  a  shovel.  Care  should  be  exercised  that  this  is  done  before  the  con- 
crete is  allowed  to  harden,  otherwise  the  bond  will  be  destroyed  and  the 
concrete  injured  at  the  edges. 

PROTECTION.  After 
floating,  and  as  soon 
as  it  can  be  done  with- 
out marking  or  pitt- 
ing the  surface,  the 
pavement  should  be 
sprinkled  with  water, 
and  kept  wet  for  at 
least  three  days;  or 
after  sprinkling  for  one 
day,  from  one  to  two 
inches  of  sand  or  dirt 
may  be  spread  over 
the  surface  and  wetted 
as  often  as  required. 
The  q  ualitv  of  the  con- 

32 — Near  view  of  steel  expansion  joint  in  place. 

much  upon  the  treat- 
ment and  curing  re- 
ceived during  the  first 
few  days,  and  it  is  im-  L_jJ>* 

portant  that  the  con-  ~***^ 

crete  be  kept  well 
sprinkled  and  not  per- 
mitted to  dry  out.  In 
hot  weather,  the  pave- 
ment should  not  be 
thrown  open  to  traffic 
until  at  least  ten  days 
old,  and  in  cool  weath- 
er traffic  should  be 

kent    nff    even    Inno-^r          Figure  33— Baker    plates,    used   for    protecting    expansion   j 
Kept  OJ      even      Ollgei.  being  prepared  for  use. 

Expansion  Joints. 

That  expansion  and 
contraction  of  con- 
crete pavements  must  be  provided  for  is  admitted  by  all,  but  how  best  to  do 
this,  where  and  how  far  apart  and  how  wide  to  make  the  joints  are 
probably  the  most  discussed  questions  in  connection  with  this  class  of 
construction.  That  joints  of  any  character  running  parallel  with  the 
axis  of  the  street  should  not  be  used  has  been  clearly  demonstrated  in 

—39— 


Two  thicknesses  of  tar  paper  of  a  width 
equal  to  the  thickness  of  the  pavement  provide  the  separation. 
The  plates  have  the  same  crown  as  the  roadway  and  are  shipped 
flat,  the  prongs  being  bent  out  with  a  short  length  of  pipe  just 
before  placing. 


Concrete     V  a  r  c  m  ent  s ,     iS  idewal  k  «v ,     C  urb    and    Gutter 


practically  every  case  where  such  joints  have  been  made,  but  room  for 
expansion  must  always  be  left  between  the  edges  of  the  pavement  and 
the  curb;  one-half  inch  joint  being  ample  for  the  widest  pavements. 
Transverse  joints  should  be  placed  across  the  street  perpendicular  to 
the  axis  of  the  pavement,  not  over  thirty  feet  apart,  and  all  expansion 
joints  should  extend  through  the  entire  thickness  of  the  pavement. 
Open  transverse  joints  should  be  as  near  one-quarter  of  an  inch  in 
width  as  it  is  practicable  to  make  them,  but  not  over  one-half  inch.  They 
should  be  filled  with  suitable  bitumen  which  will  not  become  soft  and 
run  out  in  hot  weather,  nor  hard  and  brittle  and  chip  out  in  cold  weather; 
and  the  edges  of  the  concrete  at  the  joints  should  be  protected  with 
suitable  metal  protecting  plates. 

A  satisfactory  transverse  joint,  illustrated  in  Figure  33  may  be 
formed  by  clamping  the  metal  protecting  plates  to  34  inch  metal  division 
plates  or  to  two  thicknesses  of  */g  inch  tar  paper  or  felt  cut  to  conform 
to  the  cross  section  of  the  pavement.  The  assembled  joint  is  staked  into 
position  on  the  sub-grade  and  concreted  in  place.  Where  tar  paper  or 
felt  is  used,  this  is  left  in  place,  but  wliere  metal  division  plates  are 
used  they  should  be  withdrawn  after  the  concrete  has  hardened  suffi- 
ciently to  hold  the  protecting  plates.  The  space  is  later  filled  with 
suitable  filler. 

Gravel  Shoulders.  On  lightly  travelled  highways,  the  traffic  can 
generally  be  handled  over  a  width  of  concrete  much  narro\ver  than  is 
necessary  for  the  trunk  roads.  In  order  to  provide  for  passing  vehicles, 
the  width  can  be  increased  by  adding  shoulders  of  gravel  containing 
clay  as  a  binder.  Since  such  shoulders  are  only  used  for  the  purpose 
of  turning  out,  the  wear  is  not  excessive.  Figure  1  illustrates  the 
section  recommended  for  the  shoulders. 


Fijure  34—  Filling  the  expansion  joint. 


Universal    Portland     Cement     Co. 


The  following  table  from  "Engineering  and  Contracting"  for  April 
3,  1912,  gives  an  idea  of  the  cost  of  concrete  pavements  constructed 
during  1911,  in  a  number  of  cities. 

Table  Showing  Amount,  Average  Price  and  Some  Details 
of  Concrete  Pavements  in  1911,  in  a  Number  of  Cities 


CITIES 

Sq.  Yds. 

Av.  price  per 
sq.  yd.  includ 
ing  grading. 

Guar- 
antee 
Years 

Total  thick- 
ness of  pave- 
ment, inches 

Pro- 
por- 
tions. 

Portland,  Me  

ll,2S8x 

$1.29 

6 

1:2^:5 

Lynn,  Mass  

21,402 

.70 

5 

G 

1:2     :4 

Trenton,  N.  J  

2,826 

.44 

1 

6 

1:2  1/2"  :5 

Seymour,  Ind  

1,250 

.90 

3 

7 

I*1 

Edwardsville,  111  

8,950 

.40 

y.. 

72 

1:3     :5 

Alpena,  Mich  

13,000 

.30 

8 

1:6 

Kscanaba,  Mich  

12,000 

.87 

6/4 

Fond  du  Lac,  Wis  

ll,043x 

.25 

5 

Q]/2 

1:2^:5 

Sheboygan,  Wis  

19,860x 

.28 

&A5 

Bemidji,  Minn  

19,826 

.90* 

2 

5 

1:3^9 

Burlington,  Iowa  

4,489 

.34 

5 

6% 

1:2  ":5 

Cedar  Rapids,  Iowa  

2,178 

.  16* 

76 

1  :3     :5 

Davenport,  Iowa  

13,208 

.23* 

2 

76 

1:3     :5 

Fort  Dodge,  Iowa  

7,900 

.60 

5 

77 

1:3     :5 

Marshalltown,  Iowa  

14,000 

.18 

7 

1:3     :5 

Mason  City,  Iowa  

42,000 

.30 

5 

7s 

1  :2     :5 

Sioux  City,  Iowa  

100,000 

.20 

5 

1-3     :4^ 

Kansas  City,  Mo  

81,000 

.05 

5 

6 

Grand  Island,  Neb  

3,754 

.30 

Omaha,  Neb  

4,485 

South  Omaha,  Neb  

13,200 

.30 

5 

6io 

1:2^:5 

Kansas  City,  Kas  

.09 

5 

6 

Ottawa,  Kans  

996 

.03* 

2 

6 

i:2     :3 

Wichita,  Kans  

2,137 

.00* 

2 

6 

1:2     :4 

Billings,  Mont  

2,000 

2.25 

g 

7}-'211 

1:6 

Boise,  Idaho  

23,166 

1.  12* 

6 

1:3     :512 

Grand  Junction,  Colo  

18,000 

2.20 

71  :! 

1:3     :6 

Vancouver,  Wash  

15,220 

1.15 

5 

Portland,  Ore  

31,417 

Salem,  Ore  

85,266 

1.30* 

6 

1:2'    :4 

*Does  not  include  grading.         xlleinforced. 

Jl-6  mix;  1-2  surface.  25-inch  base,  1-3-5  mix;  2  inch  top  of  1  cement,  1  small  gravel, 
1  sand.  34  inch  base,  2  inch  wearing  surface.  45  inch  base,  1-23^-5;  1^  inch  top,  1  cement, 
1  sand,  1  gravel.  56>2  inch  at  gutter,  8l/2  inch  at  center.  °5  inch  1-3-5  mix;  2  inch  top  1-2. 
7  5  inch  base,  1-3-5;  2  inch  top  1-1-1.  85  inch  base  1-2-5;  2  inch  top  1-2.  »!%  inch  2-3 grout: 
5]^  inch  1-7  mix.  106  inch  and  8  inch.  lxLaid  in  6  inch  gravel  base;  pavement;  6  inch  1-6 
gravel  base  and  1}-^  inch  1-2  mortar  top.  12Also  1-3-7.  135  inch  base,  2  inch  top.  145inch 
of  1-3-5  and  1%  inch  of  1-2. 


Concrete     Pavements,     Sidewalks,     Curb     and     Gutter 
Pavement  Calculations 

Width  of  Concrete  Sq.  Yards  per  100  ft. 

9  feet...  ...100 

12  feet 133| 

14  feet 155  5/9 

16  feet 177  7/9 

18  feet 200 

20  feet 222  2/9 

To  obtain  cubic  yards  of  concrete  required  for  pavement 

4  inch  thick  multiply  area  in  square  yards  by  4/36,  or 0.  Ill  11 

5  inch  thick  multiply  area  in  square  yards  by  5/36,  or 0. 13889 

6  inch  thick  multiply  area  in  square  yards  by  6/36,  or 0. 16667 

7  inch  thick  multiply  area  in  square  yards  by  7/36,  or 0. 19444 

8  inch  thick  multiply  area  in  square  yards  by  8/36,  or 0. 22222 

1 1/2  inch  thick  multiply  area  in  square  yards  by  1/24,  or 0. 04167 

2  inch  thick  multiply  area  in  square  yards  by  1/18,  or 0. 05556 

Assuming  1  sack  cement  =  1  cu.  ft.,  1  cu.  yd.  of  concrete  requires: 

Mixture  Bbls.  Cement  Cu.  Yds.  Sand  Cu.  Yds.  Gravel 

1:1^:3  1.91  0.42  0.85 

1:2     :3  1.74  0.52  0.77 

1:2     :4  1.51  0.45  0.89 

1:2^:5  1.24  0.46  092 

1:3     :5  1.16  0.52  0.86 

\-.\Yz  3.87  0.86 

1:2  3.21  0.95 


Examples 

Example  No.  1  :    Road  or  pavement  1500  feet  long,  18  feet  wide,  one-course,  7  inches 
thick,  mixture 


15  (length  in  hundred  feet)  200  (number  of  square  yards  per  100  feet  length)  0.19444 
(number  of  cubic  yards  per  square  yard  area)  =  583.32  cubic  yards  of  concrete. 

f  1.91  =1111  barrels  cement 
5S3.-32    \  0.  42  =    245  cubic  yards  sand 
(  0.  85  =    496  cubic  yards  gravel 


Example  No.  2:    Road  or  pavement  1500  feet  long,  18  feet  wide;    two-course;   base  6 
inches  thick,  mixture  1:3:5,  top  1M  inches  thick,  mixture  1:1^>. 

I 

(1.16  = 
]  0. 52  = 

[  0. 86  = 


Base— 

15  x  200  x  0. 16667  =  500. 01  cubic  yards 

=580  barrels  cement 
500. 01    \  0. 52  =  260  cubic  yards  sand 
430  cubic  yards  gravel 

Top— 

15  x  200  x  0. 04167  =  12.5.  01  cubic  yards 

i»«  AI    /  s-87  =  484  barrels  cement 
L*5.  ui     ^  Q  86  =  log  cubic  yardg  ^j 

Total— 

580  +  484  =  1064  barrels  cement 
260  +  108  =    368  cubic  yards  sand 
430  +      0  =    430  cubic  yards  gravel 


U  niv  er  sal    Portland     C  ement     Co. 


Concrete  Sidewalk  Construction 

Concrete  is  now  accepted  as  the  ideal  material  for  sidewalk  con- 
struction. The  great  latitude  or  methods  of  operation  make  many 
different  types  of  construction  possible,  and  it  is  with  regret  that  the 
prevalence  of  the  steel  trowel  finished  surface  is  acknowledged. 

A  glassy  finfeh  is  far  from  ideal  both  as  to  beauty  and  safety  of 
pedestrians.     All  modern  architects  feature  the  ideal  surface 
obtained  by  bush  hammering  or  rough  casting  our  concrete 
surfaces  because  of  the  pleasing  effect  obtained.     Yet  many 
persist  in  demanding  a  '"shine"  upon  the  sidewalks. 

Another  custom 

now  quite  general  is 

the    specification     of 

two -course 

Advantages     sidewalk 
or  one-  •.        rr,1  . 

coarse  work  work-  .  This 
condition 
will  not  remain,  how- 
ever, since  more  and 
more  of  our  cities  are 
beginning  to  appreci- 
ate the  advantages 
of  the  monolithic 
one-course  slab.  With 
this  treatment,  it  is 
possible  for  the  work 


55 — Breaking   up 
alk  construction. 


.estone  flags   making  way  for 


to  he  its  own  inspector 
because  of  the  impos- 
sibility cf  finishing  the  concrete,  if  enough  cement  has  not  been  used  in 
the  mix. 

Another  advantage  in  the  one-course  sidewalk  is  uniform  character; 
the  entire  mass  is  wearing  surface.  One  layer  naturally  can  be  placed 
more  cheaply  thrfn  two,  and  the  additional  strength  is  such  that  the 
equivalent  of  a  five-inch  two-course  walk  can  probably  be  obtained  by 
four  and  one-half  inches  of  the  richer  mix,  placed  in  one  operation. 

The'n,  too,  the  actual  amount  of  materials  are  nearly  identical  for 
each  type.  Below  is  shown  the  comparison  of  the  two  constructions 
based  on  100  square  feet  of  surface: 


TYPE 

Mixture 

Bbls. 
Cement 

Cu.  Yds. 
Sand 

Cu.  Yds. 
Gravel 

Total 
Cost 

Materials 

5-inch  Two-Course  .... 

1:2^:5  base 

1:1  J-3  top 

2.52 

.'80 

1.21 

$6.79 

4^-inch  One-Course.  .  . 

1:2     :3 

2.42 

.73 

1.08 

$6.16 

Concrete    Pare  tu  e  n  t  .v ,     Sidewalks,     Curb    and    Gutter 

The  foregoing  calculations  were  made  on  the  same  basis  for  both 
the  5-inch  and  the  4 i 2-inch  walk;  viz.  Portland  cement  at  $1.50  net,  sand 
at  $1/25  per  en.  yd.  and  gravel  at  $1.50  per  cu.  yd.  It  is  plain,  then, 
that  the  saving  is  not  alone  in  labor,  but  in  cost  of  materials. 

Foundation.  In  the  construction  of  a  walk,  it  is  necessary  that 
the  foundation  be  built  so  that  neither  time  nor  the  elements  can  change 
its  ability  to  support  the  walk.  Improperly  constructed  fills  and  poor 
sub-bases  result  in  a  great  many  defective  walks.  Typical  examples  of 

such  defects  are  shown 
in  Figures  36  and  38. 
It  is  true  that  a  crack 
through  the  center  of 
a  walk  may  not  nec- 
essitate its  rebuild- 
ing, but  when  it  is 
understood  that  a 
perfect  walk  can  be 
obtained  with  so  little 
additional  effort,  such 
failures  are  inexcus- 
able. If  the  founda- 
tion settles  to  any 
great  extent,  the  walk 
will  practically  be  de- 
stroyed unless  it  is 
built  strong  enough  to  resist  breaking,  and  tilt  instead. 

Sub-Grade.  As  walks  seldom  rest  upon  the  top  of  the  ground  it  is 
usually  necessary  to  prepare  the  sub-grade  upon  which  the  sub-base  or 
foundation  is  laid.  This  is  done  by  either  of  the  two  methods  shown  in 
Figure  37.  If  the  soil  at  the  excavated  grade  is  firm  and  solid,  there  is 


Figure  36 — Crack  through  center  of  a  6  foot  walk  resulting  from 
poor  foundation. 


/*    /oio  m  grot/net. 


Ftfure  37 — Detail  of  sidewalk. 


Universal    Portland    Cement     Co. 


no  necessity  for  further  preparation,  but  if  it  contains  any  soft  or  spongy 
places,  these  should  be  removed  and  the  holes  filled  with  firm  material 
packed  solidly.  When  the  sub-grade  occurs  on  fills,  its  preparation 
requires  more  care,  and  it  is  not  strange  that  many  failures  can  be  traced 
to  improperly  made  fills.  The  material  should  be  placed  and  tamped 
in  layers  not  to  exceed  6  inches  in  thickness.  When  the  material  and 
conditions  will  permit,  the  intelligent  use  of  water  will  assist  greatly 
in  compacting  a  fill.  The  reason  for  extending  the  fill  and  sub-base 
beyond  the  walk  at  the  line  of  the  sub-grade,  shown  in  Figure  37, 
is  made  evident  by  Figure  38.  Here  the  breaking  off  of  the  edge  of 
the  walk  was  due  to  the  fact  that  the  fill  was  made  too  narrow,  and 
then  left  unprotected.  The  sides  of  the  fill  and  sub-base  should  be 
given  a  slope  of  about  1:1/^,  so  that  it  will  not  slip  away,  and  wThen 
granular  materials  are  used,  the  slope  should  be  banked  with  sod  or  clay. 

The  sub-base  should  be  flooded  and  tamped  on  the  sub-grade  to  the 
proper  level,  giving  a  pitch  toward  the  gutter  of  %"  to  the  foot.  This 
should  be  done  on  approximately  the  lines  shown  in  Figure  37,  though 
the  sub-grade  may  be  an  imaginary  line  as  is  the  case  when  fills  are  made 
of  the  same  material  as  used  in  the  sub-base. 

Forms.  Two-inch  lumber  is  in  general  use  for  sidewalk  forms, 
although  several  types  of  metal  forms  possess  particular  merit,  and  are 
described  later  under  "Commercial  Forms." 

Curv  ^or  f°rmmg  curves,  a  strip  of  metal  or  thin  wood  can  be  used, 

being  careful  to  drive  enough  stakes  to  hold  in  position  against 
tamping  of  the  concrete. 


Figure  38 — -The  illustration  shows  plainly  the  necessity  of  providing  a  proper  fill  and  then  preserving  it. 
In  this  case  the  fill  was  of  sand  and  scarcely  wider  chan  the  walk.  Not  being  properly  protected 
it  was  rapidly  destroyed  and  at  this  point  the  walk  was  undermined  nearly  y$  of  its  width. 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 


I 
1 

1 

1 

—  s 

'                         S 

•           I             ( 

luV 

• 
1 

^-D-    IT   ITU  1 

0     0    0  0—  ( 

1                                                    DETAILS 

Figure  39  —  Forms  for  sidewalk  construction. 

To  insure  a  perfect  joint  between  adjoining  slabs  a  metal  cross  form 

may  be.  used  made  up  of  ¥%'  metal  with  stiffeners  along  the  top  edge. 

c        f  A  very  satisfactory  joint  can  be  obtained,  however,  by  tamping 

the  concrete  against  a  wooden  cross  form  prior  to  its  removal 

for  filling  in  the  slab  adjacent.    This  construction  is  shown  very  plainly 

in  Figure  39. 

As  soon  as  the  side  forms  are  placed  and  securely  staked  to  the 


Figure  40 — The  importance  of  exercising  care  in  placing  a  joint  or  surface  marking  in  a  walk  imme- 
diately over  the  joint  in  the  base  is  shown  above.  In  this  case  the  surface  marking  was  a  little 
to  one  side  of  the  joint  in  the  base  and  parallel  with  it.  A  slight  motion  in  the  foundation  caused 
a  crack  to  occur  immediately  over  the  joint  in  the  base,  but  it  would  have  followed  the  surface 
marking  if  this  had  been  properly  placed. 


Universal    Portland     Cement     Co. 


finished  grade,  the  division  lines  should  be  marked  plainly  upon  each  side 
of  the  work  with  wax  crayon.  This  locates  the  position  of  the  cross  form 
as  well  as  the  dividing  line  which  should  cut  through  by  the  groover 
exactly  at  these  points  after  the  top  is  placed.  Figure  40,  shows  an 
example  where  the  divisions  in  the  top  and  base  were  not  coincident. 

The  question  of  width  of  sidewalks  is  a  very  important  one.  The 
tendency  has  been  to  make  the  sidewalks  too  narrow  and  the  street  pave- 
ments too  wide  in  both  business  and  residence  streets.  The  pavement 
should  be  narrow  on  a  residence  street,  for  economy,  width  not  being 
necessary  for  the  traffic,  and  cost,  comfort  and  beauty  being  favor- 
ably affected  by  reducing  the  width  of  the  pavement  and  throwing  the 
space  thus  saved  into  a  lawn,  preferably  between  the  curb  and  the  paved 
strip  of  sidewalk.  If  a  street  railway  should  later  occupy  the  street,  or 
business  traffic  should  crowd  it,  the  curbs  can  be  set  back,  and  the  street 
pavement  widened  at  the  first  necessity  of  repaving.  This  has  been  done 
in  Indianapolis,  where  the  ratio  of  paved  street  surface  on  residence 
streets  without  street  car  tracks  is  50%  of  the  total  street  width  in 
narrow  streets,  and  even  less  in  streets  of  over  60  feet  between  prop 
erty  lines. 

Experience  clearly  shows  that  since  pedestrians  must  needs  travel 
in  both  directions  on  business  streets,  the  sidewalks  should  be 
as  w^e  as  P°ssible,  even  at  the  expense  of  comfort  in  the  street. 
Many  more  people  are  delayed  and  inconvenienced  by  narrow 
sidewalks  than  by  narrow  streets,  if  the  street  traffic  is  properly  regulated 
and  required  to  keep  always  to  the  right  side  of  the  street. 

There  must  be  a  difference  between  wholesale  and  retail  streets,  and 
there  should  be  a  regulation  of  the  use  of  sidewalks  as  well  as  of  streets. 


Figure  41 — The  necessity  for  providing  perfect  joints  is  distinctly  shown  above  where  the  joints 
of  the  old  work  were  continued  through  the  new,  due  to  imperfect  joints  It  is  evident  thac  had 
the  joint  in  the  center  of  the  walk  opened,  the  cracks  would  not  have  occurred:  also  that  the  cracks 
discontinued  at  points  where  real  ioints  were  provided 


Concrete    Pare  m  c  n  t  s ,     Side  ic  a  I  k  s ,     Curb    and    Gutter 


On  a  retail  business  street,  the  first  and  most  important  consideration 
is  the  pedestrian  traffic.  Second  is  the  regularly  moving  traffic,  including 
the  momentary  stoppage  of  vehicles  to  let  off  passengers,  and  third  is 
the  standing  of  vehicles  along  the  curb  while  the  occupants  are  attending 
to  business  in  shops,  stores  and  offices. 

Fifteen  feet  is  a  narrow  sidewalk  for  a  busy  retail  street,  and  should  be 
the  minimum  limit  if  it  is  in  any  way  possible  to  take  care  of  the  street 

traffic  on  the  remainder  of  the 
street  width. 

On  wholesale  streets,  street 
pavement  width  is  somewhat 
more  important  if  wagons 
must  back  up  to  the  curb  for 
loading  and  unloading;  and 
foot  traffic  is  much  less.  But 
there  should  be  strict  regula- 
tion of  the  use  of  the  side- 
walks in  handling  goods, 
otherwise  the  passageway  for 
pedestrians  will  be  reduced 
enough  to  cause  inconven- 
ience and  delay. 

Regardless   of    the   width 


Figure  42  —  Showing  the  operation  of  cutting  through 
the  top  surface  in  two-course  work  with  a  pointing 
trowel  before  using  the  grooving  tool. 


slab  should  contain  more  than 

36  square  feet  an    the  length 

,..       f   ,  ,       should  not  exceed 

Size  of  slabs  •,  •      i. 

one  and  one-halt 
times  the  width.  This  regu- 
lation, of  course,  applies  only 
to  walks  resting  directly  upon 
the  ground.  In  the  business 
districts,  vaults  under  the 
sidewalks  are  desirable  and 
are  generally  obtained  with 
concrete  arches  supported 
upon  steel  I-beams  or  by  rein- 
forcing the  concrete.  Where 
reinforcing  is  used,  the  size 
of  the  slab  is  immaterial. 


of  the  sidewalk,  no  individual 


Figure   43  —  After   cutting 

trowel  the  joint  is  finished  wi 


through   the    top   with    the 
th  a  groover. 


In  the  business  section,  the  thickness  will  generally  exceed  C  inches 

while  in  the  residence  district,  five  inches  is  sufficient  for  the  ordinary 

_,  .  street  sidewalk,  and  four  and  one-half  inches  in  one-course  work. 

The  thickness  of  the  wearing  course  for  two-course  sidewalk  is 

influenced  by  the  wear  to  be  received.    In  general  the  top  of  a  five-inch 

walk  should  be  three-quarters  of  an  inch  thick,  which  should  be  increased 

for  the  walks  of  greater  thickness  or  carrying  more  traffic. 

Surface  Drainage.     Since   the   slabs   are   constructed   of   uniform 
thickness,  drainage  must  be  obtained  by  tilting  the  walk  slightly.      For 


Universal    Portland    Cement    Co. 


Figure  44 — Template  for  sidewalk  construction. 


Figure  45 — Strike  Board  used  for 
gauging  base  and   striking  top. 


Water 


this  purpose  the  form  nearest  the  street  should 
be  placed  slightly  below  the  inside  form,  the 
accepted  pitch  being  one-quarter  of  an  inch 
to  the  foot.  Where  walks  are  placed  through 
yards,  parks  or  private  grounds,  a  very  satis- 
factory method  of  obtaining  drainage  is  to 
give  the  top  a  slight  crown,  and  accomplished 
with  a  curved  template,  as  shown  in  Figure  44. 
The  amount  of  pitch  should  be  about  equal 
to  one-quarter  of  an  inch  to  the  foot  from  the 
center  to  the  edges ;  thus  a  four-foot  walk  would  have  a  one-half  inch  crown. 

Proportions.  Although  there  may  be  a  great  deal  of  allowable 
variation  in  proportions  for  concrete  sidewalks,  it  is  safe  to  say  that  for 
all  purposes  the  best  results  can  be  obtained  with  the  use  of  a  mixture  of 
one  (1)  part  Portland  cement,  to  two  and  one-half  (2^)  parts 
of  fine  aggregate,  to  five  (5)  parts  of  coarse  aggregate  for  the 
concrete.  For  the  mortar  top  the  mixture  should  not  be  leaner  than  one 

(1)   part  Portland  cement  to 
.'-c^np^f^-^^, —      two    (-2)   parts   of  fine  aggre- 
gate.   The  same  precautions 
jLJBP**      are  necessary  in  maintaining 
the    proportions    as   outlined 
-. .  •    "  heretofore.     The  consistency 

of  the  base  concrete  should  be 
such  that  moisture  just  ap- 
pears on  the  surface  after 
thorough  tamping.  For  the 
top  mixture  enough  water 
should  be  used  so  that  the 
mortar  will  not  show  a  grain, 
^51  but  spread  easily  under  the 

Figure  46— Showing  the  edger  in  operation  Straight    edge   Or  template;    it 


Concrete     Pavements,     Side  walks,     Curb    and    Gutter 

should  not  be  made  thin  enough  to  flow,  sincn  mortar  of  this  kind  is  of 
inferior  quality. 

Placing.  When  the  sub-grade  and  sub-base  have  been  properly 
prepared  and  the  cross-forms  placed,  the  concrete  can  be  deposited, 
starting  at  one  end  of  the  work  and  filling  and  striking  off  with  a  straight 
edge  up  to  the  first  cross  form.  The  excess  material  can  be  scraped  over 
into  the  next  form.  The  concrete  is  tamped  down,  which  will  probably 
provide  the  required  top  thickness.  This  can  be  gauged  by  using  a 
strike  similar  to  that  shown  in  Figure  45,  in  which  the  ends  are  notched 
out  to  the  proper  thickness.  One  side  may  be  used  for  a  gauge,  and  the 
other  side  for  leveling  the  concrete. 

With  the  tamping  in  the  first  slab  complete,  the  cross  form  may  be 
removed  and  the  next  slab  filled  and  tamped  in  the  same  manner,  being 
careful  not  to  break  down  the  perpendicular  division  joint.  The 
°kJect  °f  this  extreme  care  in  providing  joints  is  to  insure  against 
the  appearance  of  cracks,  due  to  slight,  uneven  settlement  in  the 
foundation. 

As  soon  as  possible  after  the  base  is  tamped,  the  top  mortar  should  be 
applied  and  spread  evenly  over  the  surface,  using  the  side  forms  as  guides. 
When  sufficiently  hardened,  the  top  should  be  floated  with  a  wooden 
float.  The  divisions  should  be  cut  through  with  a  pointing  trowel,  exactly 
above  the  divisions  in  the  base,  and  which  were  previously  located  by 
marking  the  side  forms  with  wax  crayon. 

Moving  the  straight  edge  to  the  left  a  distance  equal  to  half  the  width 

of  the  groover,  allows  the  joint  to  be  molded  into  shape.     The  edges 

fi   .  ,    should  now  be  finished  by  running  the  edger  along  the  forms. 

The  wooden  board  has  probably  left  a  few  indentations  in 

the  walk,  which  should  be  floated  out.     Without  using  a  straight  edge, 

the  groover  should  now  be  run  over  the  divisions  and  the  edger  along  the 

side  forms  to  leave  the  work  with  an  unmarred  surface. 

In  a  number  of  cities,  the  steel  trowel  finish  is  still  common  practice. 

The  operations  are  identical  with  those  described  for  the  wooden  float, 

Trowel  finish  w^h  ^ie  exception  that  the  first  finishing  employs  both  the 

wooden  and  steel  trowel,  but  as  it  is  not  necessary  to  finish 

the  joints  twice,  the  labor  is  about  the  same. 

For  constructing  a  one-course  sidewalk,  the  operations  of  form  setting 

and   mixing  are  identical    with   the  two-course  work,  except  that  the 

forms  need  not  be  as  wide  and  the  mixing  of  the  top  mortar  is 

One-course    dispensed  with.     In  filling  the  forms  it  is  necessary  to  heap  up 

sidewalk        the  concrete  slightly  so  that  tamping  will  just  bring  to  grade. 

A  wetter  mixture  is    recommended   than   for   the    two-course 

work  so    that   an   easy   working   mortar  is  provided.     The  use  of  the 

special  tamper  shown  in   figure   16  will  be  of  assistance  in  forcing  the 

coarser  aggregate  away  from  the  surface  and  in  flushing  the  mortar  to 

the  top. 

Carelessness  of  one  kind  encourages  another  and  when  walks  are 

being  laid  where  it  is  possible  to  run  in  long  stretches,  one  frequently  sees 

Fractional  a  fractional  part  of  a  slab  left  over  at  quitting  time,  and  when 

slabs  work  is  resumed,  new  concrete  is  placed  against  the  portion  which 


Universal    Portland    Cement     Co. 


was  previously  laid  and  a  top  spread  over  the  whole.  As  the  bond 
between  the  two  concrete  bodies  is  weak  at  best,  a  crack  will  invariably 
occur  at  the  juncture.  A  fractional  part  of  a  slab  should  never  be  left 
over  upon  suspending  work  even  for  the  noon  hour.  The  concrete  should 
be  packed  against  the  cross  forms  so  that  when  placing  of  concrete  is 
resumed,  it  will  start  from  a  vertical  joint  between  abutting  slabs.  Any 
concrete  left  over  at  the  time  work  is  suspended  should  be  discarded  if 

the  work  is  stopped 
long  enough  to  permit 
of  any  hardening  or 
perceptible  drying  out 
of  the  mass. 

Wherever  a  walk 
is  crossed  by  a  drive- 

>    thef 
thickness  of 

the  base  should  be  in- 
creased at  least  two 
inches  and  the  top 
should  have  a  mini- 
mum thickness  of  one 
and  one-quarter 
inches. 

Walks  are    some- 
times   laid  with    too 


Driveway 


ased     by    hardened    concrete 
work   allowed   to  remain   in 


Grades 


Figure  47 — Fractional  slab  a 
over  from  the  previous  day's 
form. 

steep    a    pitch     for 
safety,  and  although 

there    may    be 

little  objection 
to  them  in  fair 
weather,  such  walks 
become  impassable 
when  iced  over  dur- 
ing the  winter  season. 
Wooden  walks  are 
sometimes  laid  over 
the  cement  to  provide 
a  surer  foothold,  but 
this  expedient  would 
be  unnecessary  if 
steps  were  built  where 
the  grade  exceeds 
twenty  per  cent. 
Lesser  grades  are  improved  by  laying  the  run  with  sufficient  slope  to 
afford  drainage  and  putting  in  risers  at  suitable  intervals.  A  further 
improvement  is  to  give  a  roughened  finish  to  the  run  by  means  of  a 
wooden  trowel  or  grooving  tool,  or  by  imbedding  safety  tread  strips  as 
shown  in  Figure  48. 

The  comfort  of  pedestrians  demands  that  the  grade  in  a  walk  shall 
not  change  suddenly,  excepting  where  steps  are  advisable.     It  is  not 

—51— 


Figure  48 — A  novel  way  of  providing  for  the  comfort  of  pedes- 
trians on  steep  grades  by  inserting  safety  tread  strips  in  the 
walk  when  laid. 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 


unusual  to  find  a  break  in  continuity  of  the  grade,  such  as  is  illustrated  in 

Figure  50.      Here,  the  higher  walk  was  built  last  and  is  connected 

de*  °f  ^°  *^e  lower  by  a  sharp  bevel.     The  passerby,  unprepared  for 

this  interruption,  is  sure  to  receive  a  shock.     If  this  walk  had 

been  built  right,  the  change  in  grade  would  have  been  extended  over  the 

length  of  an  entire  slab.     There  was  yet  another  abrupt  change  of  grade 

between  the  point  where  the  picture  was  taken  and  the  last  crossing, 

although  the  street 
was  level  throughout 
this  distance.  It 
would  be  well  for 
every  city  and  town 
to  establish  by  ord- 
inance, the  grades  of 
sidewalks,  so  as  to 
avoid  abrupt  changes, 
excepting  where  ab- 
solutely necessary. 

Expansion  Joints. 
If  expansion  joints  are 
not  provided,  the 
walk  is  liable  to  heave 
up  or  cause  disfigura- 
tion of  the  curb 
against  which  it  is 
placed.  Common  practice  now  requires  a  ^-inch  expansion  joint  at 
least  every  50  feet.  This  is  provided  by  a  metal  or  wooden  strip  of 
the  required  width,  which  is  allowed  to  remain  in  place  until  the  walk 
has  hardened,  at  which  time  suitable  filler  is  poured  into  the  opening. 


Figure  49 — Cracking  of  sidewalk  top  due  to  expansion.  The 
section  on  the  right  being  better  bonded,  held  to  the  base  while 
the  top  on  the  adjoining  section  was  pushed  off 


figure  50 — An  abrupt  change  of  grade    that 
rise  over  the  length  of  a  slab. 


easily  have-   been  prevented    by  extending  the 


Universal    Portland    Cement     Co. 


The  practice  of  filling  the  joints  with  sand  or  earth  is  not  recommended 
since  such  materials  upon  becoming  dry  and  hard,  cannot  be  pushed 
out  by  the  expansion,  and  are  little  better  than  solid  concrete. 

Clearance  About  Trees.  When  trees  intercept  the  line  of  the 
walk,  provision  should  be  made  for  growth  else  the  trees  will  crack 
the  concrete,  as  illustrated  in  Figure  51.  The  amount  of  clearance 
around  the  trunk  will  depend  somewhat  on  the  age  and  kind  of  the 
tree,  being  greater  for  young  trees,  but  should  never  be  less  than  6 
inches  at  any  point.  Trees  whose  roots  grow  laterally,  or  near  the 
surface  of  the  ground,  are  more  troublesome  than  those  whose  roots 
grow  deeply.  Root  growth  fractures  slabs,  and  the  destruction  thus 
begun  is  completed  by  frost  action. 

Cost 

The  cost  of  cement  walk  will  vary  with  the  cost  of  materials  and 
labor  and  with  the  experience  of  the  men  doing  the  work;  also  with  the 
location  of  the  walk,  the  amount  of  walk  to  be  placed  at  one  time  and 
its  width.  Some  notes  based  on  actual  experience  relative  to  the  cost 
of  a  walk  will  doubtless  prove  of  interest.  The  cost  of  materials  given 
below  includes  delivery  on  the  work. 

Experience  shows  that  a  gang  of  six  men  can  lay  between  600  and 
800  square  feet  of  walk  in  a  day  of  ten  hours  and  700  square  feet  is 
considered  as  a  day's  work  in  arriving  at  these  figures.  This  estimate 
is  based  on  a  6-foot  walk,  having  9-inch  cinder  sub-base, 
4/^^nch  ^ase  consisting  of  one  part  cement,  2^  parts  sand 
and  5  parts  crushed  stone,  covered  with  a  %-inch  top  of  1  part 


Figure  51—  Provision  must  be  made  for  the  subsequent  growth  of  trees  or  else  bad  cracking  will  occur. 

—S3- 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 


inch  and  contained  45  per  cent  voids.  A  good  grade  of  coarse  sand 
passing  a  J^-inch  screen  was  used.  The  sand  contained  33  per  cent 
voids.  The  mixing  was  done  by  hand. 


LABOR  (TWO-COURSE) 

One  finisher  at  $.5.00  per  day 

Five  laborers  at  $£.50  per  day 


Total  cost  of  labor  (700  square  feet)  . 
Total  cost  of  labor  per  100  square  feel. 


.$  5.00 
.   12.50 

.$17.50 


$  2.50 


MATERIALS  (TWO-COURSE) 

Cement  2.  5    barrels  at  $1.50  per  barrel 

Stone      1.21  cubic  yards  at  $1. 50  per  cubic  yard 

Sand         .80  cubic  yards  at  $1.  25  per  cubic  yard 

Cinders  2.7    cubic  yards  at  $0.  50  per  cubic  yard 

Total  cost  of  materials  per  100  square  feet 

Total  cost  of  laying  100  square  feet 


1.82 
1.00 
1.35 


7.92 
$10. 42 


It  should  be  noted  that  this  estimate  provides  for  a  walk  where  an 
excavation  for  the  sub-base    was   necessary,   as  shown    in    Figure  37. 
No  addition  was  made  for  cost  of  forms  or  equipment  depreciation. 
The  cost  of  placing  one-course  work  is  probably  less  than  for  the 
two-course,  but  for  comparison,  the  labor  and  cost  of  materials 
One-course    jjave     been     considered  the  same  and  the  calculations  made 
accordingly. 


sidewalk 


Figure  53 — The  effect  produced  by  expansion  is  clearly  shown  above.  The  construction  of  the 
walk  was  first-class  but  for  the  omission  of  expansion  joints.  The  break  occurred  in  the  center 
of  the  stretch  approximately  200  feet  long,  abutting  other  and  older  walk  at  both  ends. 


Universal    Portland    Cement     Co. 


LABOR  (ONE-COURSE) 

One  finisher  at  $5.00  per  day $  5. 00 

Five  laborers  at  $2.50  per  day 12. 50 

Total  cost  of  labor  for  700  square  feet $17. 50 

Total  cost  of  labor  per  100  square  feet $  2. 50 

MATERIALS  (ONE-COURSE) 

Cement  2.42  barrels  at  $1.50  per  barrel $  3.  63 

Stone      1.08  cubic  yards  at  $1.50  per  cubic  yard 1. 62 

Sand         .73  cubic  yards  at  $1.25  per  cubic  yard 91 

Cinders  2.7    cubic  yards  at  $0.50  per  cubic  yard 1. 35 

Total  cost  of  materials  per  100  square  feet $  7. 51 


Total  cost  of  laying  100  square  feet $10. 01 

Concrete  Sidewalk  on  Limestone  Flags 

In  some  of  the  business  districts  of  our  larger  cities,  the  old  limestone 
flags  are  fast  wearing  out  making  replacement  necessary.  A  great  deal 
of  expense  may  be  saved,  provided  the  flags  are  of  sufficient  thickness, 
by  laying  a  mortar  top,  not  less  than  2  inches  thick,  directly  upon  the 
limestone.  It  is  necessary  to  clean  the  surface  thoroughly  by  chipping, 
and  anchor  a  steel  plate  tp  the  flags  for  the  curb  edge.  The  application 
of  a  cement-granite  screenings  top  completes  the  work,  and  has  proven 
successful  in  several  instances. 

Reinforced  and  Arch  Walks.  Attention  is  directed  only  toward 
pavements  which  are  laid  on  the  ground.  For  the  construction  of 
special  types  of  sidewalk,  detailed  information  is  necessary  for  the  work 
in  question  before  any  comprehensive  analysis  could  be  made  or  instruc- 
tions given  as  to  the  methods  of  undertaking. 

Sidewalk  Calculations 

Number  of  cubic  yards  of  concrete  in  100  sq.  ft.  of  sidewalk. 

3      inch  thick  =  0. 926 
3J/3  inch  thick  = 


4  inch  thick  = 
4 J4  inch  thick  = 
ty/l  inch  thick  = 

5  inch  thick  = 


.235 
.312 


.543 


%  inch  thick  =  0.  232 
1      inch  thick  =  0.  309 
Assuming  1  sack  cement  =  1  cubic  foot,  1  cubic  yard  of  concrete  requires  for: 

Mixture  Bbls.  Cement  Cu.  Yds.  Sand  Cu.  Yds.  Gravel 

1:1^=3  -91  0.42  0.85 

1:2     :3  .74  0.52  0.77 

1:2     :4  .51  0.45  0.89 

.31  0.48  0.87 

.24  0.46  0.92 

1:3     :5  .16  0.52  0.86 

1:1  4.88  0.72 

1:1H  3.87  0.86 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 


Example:     Two-course  sidewalk  400  ft.  long,  5  ft.  wide,  4}^-inch  base  mixture  1:2} o:5, 
?4-inch  top  mixture  !:!}/£. 

Area  sidewalk — 400  x  5=2,000  square  feet. 

Base- 
Cubical  contents— 20.00  x  1.312=26.2  Cubic  yards. 

(   x  1.24=32^  barrels  cement 
26.  2    j    x  0.46=12  cubic  yards  sand 

[   x  0.92=24  cubic  yards  gravel 

Top- 
Cubical  contents— 20.00  x  .232=4.64  cubic  yards 
x  3.87=18  barrels  cement 
x  0.86=  4  cubic  yards  sand 


4.64 
Total— 


Example: 
ture  1:2:3. 


18=50}^  barrels  cement 
12  +  4  =  16  cubic  yards  sand 
24  +  0=24  cubic  yards  gravel 

One-course  sidewalk  as  above  400  ft.  long,  5  ft.  wide,  4j^  inches  thick,    mix- 

Aiea  sidewalk — 400  x  5=2,000  square  feet. 
Cubical  contents — 20.00  x  1,389=27.8  cubic  yards 

!x  1.  74=48.  3.  barrels  cement 
x  0.  52=14. 5  cubic  yards  sand 
x  0.  77=21. 4  cubic  yards  gravel 


Figure  S3 — The  possibilities  of  concrete  curb  in  the  garden  are  here  very  beautifully  illustrated. 
The  curb  not  only  forms  a  pleasing  framework  for  the  flowers  but  provides  for  path  as  well. 


Universal    Portland    Cement     Co. 


Curb  and  Gutter  Construction 

While  a  sidewalk  has  a  uniform  cross  section,  which  is  well  recog- 
nized and  established,  the  same  cannot  be  said  of  the  curb,  or  curb 
and  gutter.  Every  municipality  and  every  individual  interested  in 
local  improvements  sees  the  requirements  differently.  For  instance,  in 
Chicago,  and  in  towns  where  the  country  is  level,  it  is  possible  to  main- 
tain a  constant  height  to  the  top  of  the  curb,  allowing  the  gutter  or 
street  to  take  the  pitch  necessary  for  drainage.  This  construction  would 
manifestly  be  impossible  in  Albany,  X.  Y.,  or  other  hilly  cities. 

The  uses  of  curb  are  not. 
confined  to  the  pavement  of 
city  streets,  but  extend  to  the 
beautification  of  the  lawn, 
the  flower  bed  or  the  drive- 
way. Like  other  concrete  con- 
struction, the  curb  blends  well 
with  its  surroundings  and  adds 
a  finish  not  obtainable  in  any 
other  way. 

The  greatest  variation  in 
different  localities  for  curb 
and  gutter  construc- 

tion  Probably  occurs 
at  crossings  and  at 
street  corners.  Figure  56 
shows  the  standard  curb  con- 
struction at  the  corner  and  is 
departed  from  but  slightly.  The  regulation  curb  and  gutter  is 
shown  in  Figure  57.  It  will  be  noticed  that  the  gutter  is  brought  up 
at  the  cross  walk,  so  as  to  make  the  difference  in  level  but  slightly 
noticeable  to  the  pedestrian.  This  idea  has  been  carried  further  in 
Figure  59  by  omitting  the  gutter,  or  rather  making  the  gutter  and 
curb  coincident.  This  type  requires  an  extra  gutter  outlet  at  each  side 
of  the  corner  cross 
walks,  which  is  con- 
nected underground 
to  the  corner  man- 
hole. 

Another  idea  for 
preventing  injury  to 
the  curb  through  ex- 
pansion is  illustrated 
in  Figure  60,  where 
the  sidewalk  is  carried 
out  even  with  the 
gutter.  Although  this 
design  is  said  to  or-  FJgun  55_showing  careless 

Iginate    in    Chicago,  expansion^  at  the .right,^ the 

several   towns  in  the 


Figure  54 — Showing    combination    curb    and    sidewalk 
around  a  flower  bed. 


b  has  been 

nexcusable  in  view  of  the   knowledge  of  the 
expansion. 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 


West  have  been  using  it  for  some  time.* 

In  all  the  above  designs,  a  generous  expansion  joint  is  required, 
since  the  curb,  not  being  reinforced,  cannot  resist  the  side  pressure 
occasioned  by  temperature  changes  in  an  abutting  sidewalk. 

To  provide  for  this  expansion,  without  injury  to  the  curb,  the  West 
Park  Board  of  Chicago,  uses  the  design  shown  in  Figure  61,  and 


A  patent  has  been  granted  on  this  construction. 


1 


I 'ex pans/ 
f 


/  "expansion Joint) 


Sidewalk 


"expansion  Join  f-J 


/'expansion  jcmf 


Figure  56— Curb  layout  at  crossing. 


Universal    P  ortland    Cement    Co. 


Jexpans  ion  joint  f^ 


Sidewa/k 


1  '  e  /  p  an  s  ion  Join  t 


r 

A 


\Jojnts 


t 


/'expansion  joint  J 


..1 


Section  A-A 
Curb  and  Gutter 


Section  B-B 
Curb  and  Gutter 


Fj^ure  57 — Curb  and  gutter  at  crossing.     Portion  of  gutter  raised  to  decrease  change  of  grade  be- 
tween sidewalk  and  street. 


Concrete     Pa  r  e  in  en  ts  ,     Sidewalks,     Curb     a  n  d     Guile  r 


/  <?x/?  cinsion Joint* 


oint 


Section  A-A 


Fifure  59-Sidewalk   and    Curb   and   Gutter   at   corner   designed    to   maintain  uniform  level  for  the 
pedestrian. 


Universal    Portland    Cement    Co. 


. Joi 


^ISiia_.f 


Section  B-B 


I 
I 

I 

•n 

i 
i 


'expansion  joint 


//  expan-sion 


6-0" 


..L 


Section  A- A 
Figure  60 — Flan  at  crossing  to  show  sidewalk  overlapping  curb  and  gutter. 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 


/  'expansionjoin  r£ 

*:£ldew<3lk~i:xi 
^•^•^-.^•^fi^^ZA 

r  \  v        ' 

/\s 

« 

H 

\ 

P 

T( 

—  -^. 

C"  \ 

*•-»    I 

Section  A-  A 
Curb  and  Gutter 

/"expansion 

7°'2 

/ 

6 

, 

-<3" 

«*""* 

r 

4 

1 

i 

~^~" 

7  ion  JO/SI? 

^~~ 

T 


Figure  61 — Plan  at  crossing  showing  sidewalk  overlapping  curb. 

illustrated  in  Figure  58.      A  simple   notch  is  provided  in  the  curb  on 
which  the  sidewalk  rests,  and  any  expansion  simply  causes    a  slight 
projection  of  the  side- 
walk beyond  the  curb 
line. 

An  example  of  the 
misuse  of  this  idea  is 
shown  in  Figure  55 
where  the  street  im- 
provements were  first 
completed  before  the 
sidewalk  was  placed. 
Provision  was  made 
in  the  notched  curb 
for  a  sidewalk,  such 
as  just  described,  but 
the  sidewalk  builders 
finding  the  notch  not 
properly  located,  ex 
tended  the  walk  at 

the  side,  in   contact  with  the  curb.     The   result    is    evident, 
through  carelessness  comes  the  abuse  of  an  excellent  idea. 


Figaro    58— Showing    over-lapping    sidewalk    with    notch    cut    in 
curb  to  provide  for  expansion. 


Thus, 


U  niversal    Portland    Cement     Co. 


Forms.  Wood  is  generally  used  in  building  the  forms  for  curb  and 
curb  and  gutter  work,  although  many  different  types  of  metal  forms 
have  been  devised,  which  seem  to  solve  the  problem  effectively,  both 
as  to  ease  and  cost  of  construction.  Metal  forms  have  the  advantage 
of  absolute  uniformity,  where  properly  built,  as  well  as  the  advantage 
of  long  life.  Where  a  curb  and  gutter  is  required  of  the  "sliding  grade" 
type,  the  metal  form  is  hardly  practicable,  since  the  continually  changing 
cross  section  makes  the  cost  of  templates  and  forms  almost  prohibitive. 
Two  inch  plank  are  the  most  suitable  for  the  wooden  forms,  with  width 
being  made  to  suit  the  section  required.  At  the  corners  a  metal  strip 
is  generally  used  to  give  the  required  curve. 

Materials.  Concrete  curb  and  combined  curb  and  gutter  receive 
much  harder  usage  than  the  ordinary  sidewalk  and  should  consequently 
be  constructed  of  harder  aggregate,  crushed  granite  being  none  too 
hard  for  this  purpose.  If  the  wear  is  light,  as  upon  residence  streets, 
it  is  probable  that  good  coarse  sand  and  clean  gravel  will  answer. 

Foundation.  The  preparation  of  the  .foundation  and  sub-grade  for 
curb  and  combined  curb  and  gutter  is  in  general  the  same  as  required 
for  concrete  sidewalks.  Extreme  care  is  necessary  in  compacting  the 
fill  or  sub-base  for  curb  work,  since  the  weight  per  unit  area  is  much 
greater  than  for  sidewalks  or  combined  curb  and  gutter,  which  in- 
creases the  possibility  of  damage  from  settlement. 

Curb  Construction.     In 

setting  up  the  forms  for  a 
simple  curb,  as  illustrated, 
2  x  12  inch  plank  would  be 
the  most  economical.  After 
the  excavation  is  complete 
and  the  sub-base  placed,  the 
stakes  are  driven  to  line  for 
the  back  of  the  curb,  and  to 
those  the  back  form  is  nailed. 
The  face  form  is  then  set  in 
the  same  manner,  up  to  the 
point  where  the  mortar  facing 
is  to  begin,  using  metal  tem- 
plates, placed  about  every  six 
feet,  to  give  the  required 
section  and  batter.  Batter  is 
provided  on  the  face  to  prevent 
wagon  tires  from  striking  the 
upper  corner  and  causing  ex- 
cessive wear  at  this  point. 

The  form  is  filled  with 
concrete,  tamped  down  level 
with  the  point  where  the  facing 
is  to  commence.  The  upper 
face  board  is  then  placed 
against  the  template  and  held 

by     SCreW    clamps,     extending        Figure  62-Placinf>  concrete  curb  using  metal  forms. 

—63— 


Concrete    Pavements,     Side  w  a  I  k  s,     Curb    and    Gutter 


S*  6'  ne.- plate 


Wib'lirpla 


2^, 


Figure  63 — Forms  for  construct- 
ing combined  curbs  and  gutter. 


Figure  64 — Forms  for  constructing  com- 
bined curb  and  gutter  at  cross  walk. 


from    the  face  to  the  back  form.      As  the  concreting  progresses,   the 

face  is  plastered  with  a  1:1^2  mortar,  ^  inch  or  more  in  thick- 

Filling         ness.     When  the  concrete  has  been  rammed  in  at  the  top,  the 

mortar    should   be   continued   over   the   top,    floated    and   the 

corners  rounded.     As  soon   as   possible  the    upper  face  form  should  be 

removed  and  the 
entire  surface  wood 
floated  and  trowelled. 

A  good  finish  can 
then  be  secured  by 
brushing,  keeping  the 


Finding  K 

the    brush 

up  and  down  and 
over  the  top,  which 
gives  the  most  pleas- 
ing surface.  When 
sufficiently  hardened 
so  that  the  concrete 
will  not  "cave,"  the 

Figure    65^Curb    and    gutter    construction   with    wooden   forms       lower      face     forms 
showing  the  clamps  for  holding  the  face  board  against  the  metal       should    be     removed 
ision  or  spacing  plates. 


plates  pulled  out.  The  joint  can  be  finished  by  running  the  jointing 
tool  over  the  opening. 

With   metal   forms   the  operations   are   practically   the   same.      In 

setting  them  up,  it  is  customary  to  drive  stakes  in  the  ground,  at  the 

t  I  f          junction  points,  upon  which  to  rest  the  forms.    The  templates 

15  act  in  the  double  capacity  of  providing  for  uniform  sections 

and  in  holding  the  face  and  back  rigid. 

Curb  and  Gutter  Construction.  In  building  combined  curb  and 
gutter,  using  wooden  forms,  stakes  are  first  driven  to  which  the  back 
form  is  attached  and  held  to  the  alignment  of  the  finished  grade  of  the 
curb;  likewise  the  gutter  form  is  placed. 

Cross  forms  should  be  provided  similar  to  those  used  in  sidewalk 


Universal    Portland    Cement     Co. 


construction  and  placed  about  every  six  feet,  being  careful  to  mark  their 
location  on  the  side  forms  with  wax  crayon,  since  it  is  at  these  points 
Cross  form  ^at  the  surface  joints  must  also  occur.  The  cross  forms 
1S  should  be  placed  so  as  to  provide  drainage  capacity  in  the 
gutter.  For  the  purpose  of  checking  the  slope,  an  ordinary  wooden 
mounted  level  with  a  nail  driven  into  the  bottom  at  one  end,  is  recom- 
mended. The  proper  pitch  can  be  regulated  by  the  distance  the  nail 
projects.  When  the  form  is  filled  level,  using  the  cross  forms  as  a  guide 
for  the  strike,  the  concrete  should  be  rodded  off  toward  the  curb  and 
tamped  down. 

The   curb   division  plates 
are  next  placed,  and  the  face 
board  plastered  up  on  the  in- 
side with    at  least    % 
Division     inch  of    I:ly2   mortar, 

filling  with  concrete  as 
the  plastering  progresses. 
When  the  concrete  is  all 
tamped  in,  the  mortar  is  con- 
tinued over  the  top,  rodded 
off,  floated  and  the  corners 
rounded  at  the  back  with  the 
short  radius  edger,  and  at  the 
face  with  the  curb  edger. 

As   soon   as    possible    the    ,   .-*•  z.^-ss^t  • 

Clamps     Should     be     loosened,      Figure  66— Finishing  concrete  curb  with  brush. 

the  face    form  removed  and 

the  top  placed  on  the  gutter,  using  wood  or  steel  strips  of  the  required 
Finishing  thickness,  placed  perpendicular  to  the  curb,  for  a  guide  in 
striking  off  the  mortar.  After  removing  the  guide  strips, 
the  depression  left  should  be  filled  in  with  mortar,  and  the  whole 
surface  finished  using  the  brush  as  previously  described.  The 
gutter  rounding  tool  furnishes  the  proper  corner  section  between  the 
gutter  and  curb.  A  radius  of  at  least  !}/£  inches  is  necessary  at  this 
point  to  prevent  wagon  wheels  from  striking  the  curb  corner,  since  in 
the  combined  curb  and  gutter  construction,  batter  is  not  generally 
given  to  the  curb  face. 

With  metal  forms  the  curb  and  gutter  construction  is  similar  to  the 
work  with  wooden  forms,  except  that  stakes  are  driven  for  the  forms 
to  rest  upon,  and  since  the  template  forms  the  joint,  no  cross  forms  are 
required,  and  as  the  templates  are  generally  wedged  in  from  the  outside, 
no  clamps  are  necessary.  The  templates  are  withdrawn  after  the  forms 
are  taken  away  thus  providing  perfect  joints  between  adjacent  sections, 
and  making  expansion  joints  unnecessary. 

For  building  the  conventional  drains  at  the  cross  walk,  the  elevation 
Drains       °^  ^e  Sutter  is  made  by  carrying  up  the  gutter  front  form  to 
the  proper  height,  and  using  additional  division  plates  and  clamps 
as  indicated  in  Figure  64. 


Concrete    Pare  m  e  nt  .v ,     >S  idewalks,     Curb    and    Gutter 


In  some  cities,  instead  of  plastering  the  form  with  a  facing  mortar, 
as  described,  the  concrete  is  deposited  directly  against  the  form  which 
is  then  removed;  a  dry  mix  of  one  part  cement  to  lj/2  parts  fine  aggre- 
gate a  little  finer  than  is  used  in  the  other  facing  is  then  thrown 
*n  ^ie  corner  °*  the  gutter-  This  dry  mixture,  if  it  does  not 
take  up  enough  moisture  from  the  facing  material  on  the  gutter, 
is  sprinkled  with  water  thrown  on  with  a  brush,  and  then  worked  up  or 
plastered  over  the  face  of  the  curb.  This  method,  while  faster  than 
the  one  recommended  should  be  discouraged  as  it  will  not  give  good 
results  for  the  reason  that  the  use  of  the  rich  dry  mixture  on  the  surface 

causes  excessive  hair 
checking  and  in  addi- 
tion provides  only  a 
very  thin  wearing 
surface  on  the  curb 
face. 

ON  E-  C  OURSE 
WORK.  It  is  very 
probable  that  like  the 
one-course  sidewalk 
and  street  pavement, 
the  one-course  curb 
and  curb  and  gutter 
is  practicable  and 
should  be  encour- 

Fi/fure  67—  Showing   the  need    for   proper  expansion  joints.     The         aged.      This   COnstrUC- 
failure  in  this  case  is  not  due  m  any  way  to  the  defective  quality         ..  ,,       ,.       . 

of  the  concrete  in  the  curb.  tlOIl    WOUld    eliminate 


Figure  68 — The  wisdom  of  providing  proper  joints  between  curb  and  gutter  sections  is  illustrated 
above  where  a  wash  into  an  old  catch  basin  caused  undermining  of  the  foundation.  With  but 
little  difficulty  the  foundation  was  re  prepared  and  the  sections  replaced  intact. 


Universal    Portland     C  e  m  ent     Co. 


a  large  amount  of  labor  in  plastering  the  forms  and  in  placing  the  wearing 
surface.  A  special  tamper  would  be  necessary  in  separating  the  mortar 
similar  to  one-course  sidewalk  construction.  The  mixture  used  would 
be  proportioned  about  1:2:3.  With  metal  face  plates  the  surface  could 
be  obtained  satisfactorily  by  tapping  the  form,  thus  bringing  out  the 
mortar  without  any  spading. 

Expansion  Joints.  Provision  for  expansion  joints  should  be  made 
in  building  curb,  and  curb  and  gutter,  as  well  as  sidewalks,  but  as  the 
exposure  is  not  so  great,  fewer  joints  will  probably  answer.  A  complete 
joint  1/2  mcn  wide,  every  150  feet  is  probably  sufficient  for  the  average 
conditions.  Care 
should  always  be  c — 
exercised  to  pro- 
vide a  joint  on  a 
line  with  the  edges 
of  an  abutting  side- 
walk. No  appre- 
ciable width  is 
necessary,  but  such 
provision  will 
guard  against  the 
curb  being  broken 
down  by  sidewalk 
expansion. 

The     COSt    of  Figure    69 — The    expansion    here    amounted   to    2  %    inches    but 

Kiiilrlincr    r»iirh    ftr\t\  owing  to  the  construction,  the  curb  was  not  broken.     If  proper 

lliamg    CUrD    ana  expansion  joints  had  been  provided  this  could  not  have  occurred 

Combined  CUrb  and  but  the  picture  demonstrates  clearly  that  with  this  construction 

gutter  depends,  of         no  harm  has  been  donc  either  to  the  sidewalk  or  the  curb- 


Figure  70 — Expansion  joints  are  necessary  in  curb  and  gutter  as  well  as  in  roadways  and  sidewalks 
and  when  proper  provision  for  expansion  is  not  made,  heaving  is  very  liable  to  occur,  as  illustrated. 


Concrete    Pave  m  e  n  t  s ,     Sidewalks,     Curb    and    Gutter 

course,  upon  the  cross-section  and  proportions  used.  Since  the  variation 
in  the  cross  section  is  large,  it  is  difficult  to  figure  upon  actual  costs,  but 
from  data  obtained  at  Gary,  Indiana,  the  labor  item  for  curb  construc- 
tion would  be  about  11-12  cents  per  lineal  foot.  In  constructing  curb 
and  gutter  at  Webb  City,  Mo.,  the  cost  of  labor  totaled  about  13  cents 
per  lineal  foot.  In  both  cases  the  finisher  netted  about  $5.00  per  day, 
and  the  laborer  $'-2.50  per  day. 

On  this  basis  the  cost  of  curb  construction  would  be  as  follows  for 
the  section  shown  in  Figure  56,  page  58. 

LABOR 
100  lineal  feet  curb  $11.  50 

MATERIALS 

Cement  7.  8.5  barrels  at  $1. 50  per  barrel $11.  80 

Sand       2.  70  cubic  yards  at  $1.  25  per  cubic  yard 3. 40 

Stone      4.  79  cubic  yards  at  $1.  50  per  cubic  yaid 7.  20 

Cinders  1 . 85  cubic  yards  at  $0. 50  per  cubic  yard 95 

Total  cost  of  materials  per  100  lineal  feet $23. 35 

Total  cost  of  laying  100  lineal  feet $34.  85 

Assuming  the  labor  on  combined  curb  and  gutter  at  13  cents  per 
lineal  foot  for  constructing  the  section  shown  in  Figure  57,  page  59, 
the  cost  would  be  as  follows: 

LABOR 

100  lineal  feet  curb  and  gutter  $13.00 

MATERIALS 

Cement  7.  78  barrels  at  $1.  50  per  barrel $11. 70 

Sand       2. 41  cubic  yards  at  $1.  25  per  cubic  yard 3. 10 

Gravel    3.  55  cubic  yards  at  $1.  50  per  cubic  yard 5. 35 

Total  cost  of  materials  per  100  lineal  foot $20. 15 

Total  cost  of  laying  100  lineal  feet $33. 15 

Where  crushed  granite  is  used  the  cost  would  generally  be  higher 
on  account  of  the  greater  cost  of  materials.  No  provision  has  been  made 
for  cost  of  forms  or  depreciation  on  equipment. 


Universal    Portland     Cement     Co. 


Commercial  Forms 

Concrete  for  sidewalks,  curb,  and  curb  and  gutter  is  generally  molded 
by  means  of  wooden  forms.  The  contact  of  wet  concrete  however,  tends 
to  warp  the  wood  out  of  shape,  besides  the  nailing  and  staking  necessary 
in  setting  them  up  makes  removing  difficult  without  danger  of  breaking 
or  splitting,  which  shortened  the  life  of  the  forms.  The  skilled  labor 
necessary,  time  required  in  setting,  and  cost  of  lumber  for  this  work, 
makes  these  items  enter  largely  into  the  cost  of  the  job.  Metal  forms  of 
various  types  have  been  designed  to  overcome  this  problem  by  secur- 
ing greater  durability  of  forms,  more  uniform  work,  besides  saving  labor, 
cost  and  time  required  to  complete  the  work. 

A  number  of  commercial  foims  now  on  the  market  are  briefly  illus- 
trated and  described  in  the  following  pages. 

The  Berger  Manufacturing  Company  of  Canton,  Ohio  builds  sets  of 
all  steel  forms  for  concrete  sidewalk,  curb,  and  curb  and  gutter  construc- 
tion, which  consist  of  side  rails,  4,  6  and  10  feet  in  length  and  division 
plates  or  templates,  varying  in  length  from  2  to  8  feet,  made 
"of  pressed  steel.  Figure  No.  75  shows  the  sidewalk  forms 
set  up.  The  flange  construction  and  the  slip  joint  which 


er  manu 


Berg 
facturing  Co. 


I  up. 

connects  the  side  rails  end  to  end,  gives  sufficient  strength  to  prevent 

the  forms  from  springing  out  of  shape  when  the  concrete  is  being  placed 

and  finished.     The  edges  of  both  upper  and  lower  flanges  of  the  side 

rails  are  rounded  to  permit  of  rapid  handling  without  danger  of 

Sidewalk  cutting  the  hands.     The  side  rails  are  gauged  to  the  width  of 

the  walk  by  means  of  the  steel  division  plates,  having  lugs  at 

the  ends  which  project  through  the  openings  in  the  side  rails  in  a  manner 


Figure  71 — General   view  of  concrete  curb  and   gutter  construction  showing  the  workman  tamping 
the  curb  in  the  foreground. 

-69- 


( ' o  n  c  r e t c     1> a  v e m  ents ,     Side u* alks,     Curb    and    Gutter 


Figure  73 — Berger  steel  curb  forms. 


Figure  72 — Detail  of  Berger  lock  joint. 


Figure  74 — Berger  steel  forms  for  combined 
curb  and  gutter. 


Figure  75 — Berger  steel  sidewalk  forms. 


to  be  fastened  securely  by  means  of  a  spring  wedge.  Flexible  side 
rails  4,  6,  8  and  10  feet  in  length,  with  slots  to  hold  the  division  plates, 

are  provided  for  building  curved  sections.  Curves  of  6-inch 
Crosswalk  Til(\[us  are  used  to  round  corners  and  make  intersections  where 

it  is  desired  that  these  be  rounded.  For  crosswalk  construction, 
a  rigid  5-foot  side  rail  is  used  with  a  template  curved  to  form  a  crown 
to  the  crosswalk. 

Figure  No.  73  makes  clear  how  this  principle  is  applied  to  concrete 

curb  work  by  use  of  templates  of  the  same  shape  as  a  cross  section  of 

C    b  f  rms   *^ie  ^n'sne^  curb.     The  curb  stands   18   inches  in  height,   6 

inches  in  width  at  the  top  and  9  inches  at   the  bottom.     A 

batter  1  1/2  inches  on  both  sides  facilitates  the  removal  of  the  plates  and 

gives  added  strength.      The  edges  of  the  curb  are  rounded  to  1  inch 

radius. 

The  style  of  curb  and  gutter  shown  in  Figure   74   provides   for   a 

curb  12  inches  in  height,  6  inches  thick  and   with  the  gut- 

Curb  and         ter  gjjg  7i^  jnches  high.     The  gutter  is  19  inches  wide  and 

*   dips  toward  the  curb  \Y2  inches.     The  back  of  the   curb  is 


Universal    Portland    Cement     Co. 


made  with  a  batter  of  1  inch  to  12  inches,  which  assists  in  the  im- 
mediate removal  of  the  forms  without  waiting  for  the  concrete  to  harden 
thoroughly. 

The  steel  templates  are  the  same  shape  as  a  section  taken  through 
the  finished  curb  and  gutter.  From  the  sides  of  these  templates,  lugs 
extend,  and  to  these  lugs  are  fastened  the  side  rails  as  shown  by 
Figure  72. 

Three  4-inch  side  rails,  the  same  as  those  used  in  sidewalk  construc- 
tion, are  required  for  the  back  and  a  special  7^/2-inch  rail  for  the  front 
or  gutter  side  of  the  curb,  while  one  6-inch  side  rail  is  required  for 
the  front  of  gutter.  The  sidewalk 
forms  can  be  used  with  the  curb 
and  gutter  or  curb  construction,  which 
materially  reduces  the  cost  of  the 
forms  for  any  individual  construction 
provided  the  builder  can  take  either 
sidewalk  or  curb  and  gutter  contracts. 

The  sidewalk  forms  as  shown  in 
Figure  76  are  composed  of  channels 

which  are  used    to   supplant 

the  common  2  x  4's  for  side 

rails,  and  are  built  by  the  Blaw 

Steel  Centering  Company, 
Pittsburgh,  Pa.    These  channels  come 
regularly  in  10-foot   lengths  and  are 
joined  together  by  quick  acting  slip 
joints.     The   side    rails    are    built  in 
various  heights  according  to  the  thick- 
ness of  the  walk  required.     Every  foot,  the  rails  are  slotted  and  the 
steel  dividing  plates  insure  correct  expansion  joints.    The 
plates  are  made  in  any  width  or  height  required  and  can 
be  removed  either  before  or  after  the  side  rails. 

The  curb  and  gut- 
ter forms  are  built  of 
pressed  steel  side  rails 
and 

Curb  and  steel 

gutter  forms 


Figure  76 — Blaw  forms 
Crete  sidewalk. 


in  use  building  con- 


Sidewalk  forms 


f    * 


Figure  77 — New  York  State  road 
ing  curb. 


g  Blaw  forms  for  build- 


—71— 


ing  plates  to  conform 
to  the  shape  of  the 
finished  curb  and  gut- 
ter. The  back  face  of 
the  curb  is  formed  by 
bolting  the  side  rails 
together  to  get  the 
required  height  or  by 
a  single  back  rail.  For 
the  front  face  of  the 
curb,  a  wooden  form  is 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 

used  inasmuch  as  this  strip  is  removed  immediately  after  the  concrete 
is  placed  in  order  to  allow  for  finishing. 

Figure  No.  77  gives  a  view  of  an  equipment  for  speedy  curb  con- 
struction in  use  on  the  New  York  state  road  work.    The  curb  forms  are 
built  in  practically  the  same  manner  as  the  combined  curb  and  gutter 
c  and  sidewalk  forms.     The  side  forms  are  made  of  one  single 

rail  or  a  number  of  rails  bolted  together  to  give  the  required 
height.  As  with  the  other  forms,  expansion  joints  are  provided  by  means 
of  dividing  plates  which  are  inserted  in  the  slotted  rail.  These  ex- 
pansion joints  can  be  placed  wherever  specified.  The  division  plates 
which  are  removed  independent  of  the  side  rails  or  vice  versa,  are 
furnished  for  straight  or  battered  curb.  These  forms  can  be  specially 
designed  where  extreme  sizes  are  necessary. 

The  Heltzel  steel  forms  are  manufactured  by  Jones   &  Heltzel  of 

Streator,  Illinois,  and  are  illustrated  on  the  opposite  page.   The  sidewalk 

forms  are  composed  of  rigid,  adjustable,  flexible,  and  curved  side  rails; 

also  division  plates  or  templates.     Rigid  side  rails  are  made  of  an- 

H^ltzel  nea'etl  steel'  pressed  to  shape  in  sections  of  6,  9  and  12-foot  lengths, 

with  curvilinear  openings  in  the  top  flange  to  receive  the  division 

plates  at  intervals  of  one  foot.    These  rails  are  4  inches  deep  with  a  lj^- 

inch  flange  on  the  bottom  and  a  2-inch  flange  on  top,  from  which  is  a 

depending  flange  of  one  inch,  and  are  connected  end  to  end  by  a  sleeve. 

Rigid  adjustable  side  rails  5  feet  long  are  arranged  to  telescope  a 

Sidewalk         t  or  th  j     f  n  iength   with  the  regular  side  rails.     By  their 

forms  f  .&.  ,,  ... 

use,  forms  can  be  set  in  any  odd  space  without  using  wood  to 

fill  in.  Flexible  side  rails  made  in  6,  8,  10  and  12  foot  lengths,  slotted 
at  intervals  of  one  foot  for  division  plates,  are  for  use  in  curved  sections. 

Division  plates  ]/% 
inch  thick  and  2  to  8 
feet  in  length,  have 
tapering  slots  at 
their  ends  to  make 
the  forms  easy  to  set 
up  and  take  down. 
Directly  under  each 
slot  in  the  side  rails 
is  stamped  a  protu- 
berance which  serves 
to  engage  the  division 
plate  firmly  with  the 
side  rail  when  placed 
in  position  This 
device  permits  the 
template  to  be  re- 
moved without  dis- 
turbing the  side  rails. 

Figure  78  shows 
forms  for  the  con- 
struction of  com- 

Fi&ure  78— Heltzel  forms  for  buildinj  combined  sidewalk  and  cui;b.          1)  i  n  a  t  i  O  n   S  i  d  6  W  a  1  k 


Universal    Portland    Cement    Co 


Figure  79 — Heltzel  forms  in  use  for  constructing  combined  curb  and  gutter. 


Figure  80 — Heltzel  Sidewalk  Forms. 


Concrete     P  a  r  e  m  e  nt  .v ,     <S  i  d  ewalks,     Curb     and     Gutter 


Curb  forms 


Steel    division     plates 
for   wooden   side   rails 


and  curb.  Here  a  wide  side  rail  is  used  on  the  curb  side  and  regular  side- 
walk side  rail  on  the  other.  The  templates  as  shown  in  the  illustra- 
tion are  attached  in  the  same  manner  as  those  of  the  sidewalk  forms. 

Sidewalk  side  rails  are  used  in  constructing  crosswalks  by  having 
6  or  8  division  plates  shaped  to  suit  the  cross  sectional  crown 

°f  the  Walk-     By  the  USe  °f  tW°  adJustable  "gid  side  rails'  tnese 
forms  can  be  set  to  build  a  crosswalk  for  any  width  of  street. 

The  all  steel  curb  forms  are  built  for  a  curb  20  inches  deep,  6  inches  wide 
on  top  and  8  inches  on  the  base  in  12-foot  sections,  with  provision  for 
^eniP^cs  a^  intervals  of  6  feet.     The  side  rails  are  similar  to 
those  used  for  sidewalks.    Templates  can  be  made  to  conform 
to  any  desired  specifications. 

The  all  steel  curb  and  gutter  forms  are  made  similar  to  the  combi- 

nation sidewalk  and  curb  forms,  with  3-inch  flanges.     One  wide  side 

rail  is  used  to  form  the  back  and  a  narrow  one  on  the  front. 

C"tter  With  theSe  forms  a  steel  side  rail  is  used  to  mold  tne  face  of 

forms  the  curb  and  is  held  in  position  by  a  metal  arm  or  brace  attach- 

ment.   These  forms  are  also  made  for  curved  sections. 

Division  plates  are  made  to  be  used  with  plank 
side  rails  for  curb  and  combination  curb  and 
gutter. 

The    Hotchkiss  steel    forms    are    manufactured    by    the    Hotchkiss 

Lock  Metal  Form  Company  of  Binghamton,  New  York. 

Metal  Form  Co.         The  sidewralk  forms  consist  of  straight,  rigid  side  rails, 

flexible  side  rails  for  curved  walks,  cross  pieces  or  division 

plates  of  various  lengths  and  wedge-shaped  keys  and  lugs  for  fastening 

these  parts  together.    The  rigid  side  rails  are  steel  channels  10  feet  long, 

4  or  5  inches  high  with  1-inch 
flanges  and  having  slots  at  in- 
tervals of  1  foot  to 
orm          receive  the  division 
plates.      The  flange 
at  the  top   and  bottom  help 
to  keep  them  rigid  and  when 

|P^'        ^  \        in  use  they  are  joined  end  to 

end  by  a  tongue  and  socket 
joint.  These  rigid  side  rails 
are  also  made  in  4  to  6-foot 

••^  WfcS     lengths,    slotted   at   3  and  6 

inch  intervals  to  meet  special 
conditions.  Flexible  side  rails 
are  made  4,  6,  8  and  10  feet 
long  and  4  inches  high  with 
no  flange.  They  are  built  of 
spring  steel  and  may  be  bent 
to  any  desired  curve;  those  of 
a  long  radius  being  of  heavier 
steel.  The  cross  pieces  or 
curb  f°rms  8ct  UP  l°  illustrate  division  plates  are  made  for 

—74- 


Universal    Portland    Cement     C  o . 


Figure  82 — Constructing  concrete  curb  and  gutter  using 
Hotchkiss  Lock  Metal  forms 


all  widths  of  walk.  Figure 
83  indicates  how  these  divis- 
ion plates  may  be  removed 
from  the  finished  work  with- 
out disturbing  the  surface. 
Curves  of  6-inch  radius  are 
provided  for  rounding 
corners. 

The  curb  forms  as  shown 
in  Figure  81  set  up  on  stakes 
to  represent  grade  stakes, 
show  clearly  the  tongue  and 
socket  connection,  slots  to 
receive  the  division  plates, 
templates  and  method  of 
operating  them.  These  forms 
are  built  on  the 
same  principle  as 
sidewalk  forms,  using 


Curb  forms 
the 


either  4  or  6-inch  rails  with 
templates    18  inches  high,  6 


inches  wide  on  top  and  9 
inches  on  the  bottom.  A 
batter  of  lj^  inches  on  the 
front  and  back  makes  it 
possible  to  remove  the  forms 
without  waiting  for  the 
cement  to  harden  and  gives 
the  curb  added  stability. 
The  front  edge  of  the  curb 
is  rounded  to  lj^  inches. 

The  steel  curb  and  gutter 
forms  consist  of  steel  side 
rails  the  same  as  those  with 

the    sidewalk    or 

Curb  and  b  forms  ancj  tem. 

gutter  forms     ,    .  ,   .     , 

plates  which  con- 
form in  shape  to  the  finished 

curb  and  gutter.  On  the  front  and  back  of  the  templates  are  tongues 
or  lugs  wThich  pass  through  the  slots  in  the  side  rails  and  are  held  in  place 
by  keys  on  the  outside.  They  are  provided  for  curbs  12  inches  high  at  the 
back,  6  inches  thick  and  have  a  face  6  3/2  inches  high.  The  gutter  is  18  inches 
wide  and  dips  toward  the  curb  1^  inches.  The  outer  edge  of  the  curb 
and  junction  of  the  curb  and  gutter  are  rounded  on  a  Ij^-inch  radius. 
The  back  of  the  curb  is  made  with  a  batter  of  1-inch  to  a  foot  to  allow 
quicker  removal  of  the  forms.  Two  6-inch  rails  or  three  4-inch  rails 
the  same  as  in  the  sidewalk  set  may  be  used  for  the  back  of  the  curb 
and  gutter  as  shown  in  Figure  No.  82.  This  view  illustrates  the  way 
a  cord  is  used  to  aid  in  setting  the  forms  to  the  established  line,  and 
after  the  concrete  for  the  base  has  been  placed,  how  a  plank  is  braced 

—75— 


Figure  83 — Remo 
Metal  forms. 


Lock 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 

against  the  templates  to  form  the  front  of  the  curb  while  the  concrete 
for  this  is  being  placed  and  tamped.  This  plank  is  removed  before  the 
finishing  is  commenced. 

The  Ubbink  steel  sidewalk,  curb  and  curb  and  gutter  forms  are 

manufactured   by   the   Ubbink   Steel   Form   Co.,   214-216   Pier   Street, 

Port  Washington,   Wisconsin.     The  sidewalk  form  is  com- 

Ubbink  Steel  pose(j  of  rigid  side  pieces,  4  feet,  6  feet,  and  10  feet  long, 

flexible  side  pieces  in  4  feet  and  8  feet  lengths,  cross  pieces 

6  feet  and  8  feet  long  and  6-inch  radius  curves.     At  the  top  of  Figure 


Figure  84— Ubbink  steel  sidewalk  form. 

84  is  shown  a  set  of  sidewalk  forms  set  up.  Just  below  is  a  division 
plate  or  cross  piece  indicating  the  notches  which  make  the  6-foot 
len&tns  adjustable  for  walks  from  2  feet  6  inches  to  6  feet  wide 
and  the  8  feet  lengths  are  used  for  those  from  6  feet  to  8  feet 
in  width.  For  walks  less  than  6  feet  wide  to  be  laid  in  cuts,  it  will 
probably  be  advisable  to  secure  shorter  division  plates. 

The  lower  detail  is  of  a  rigid  side  rail,  made  of  No.  10  gauge  steel, 
having  notches  adjustable  at  1-foot  intervals.  At  the  left  of  the  division 
plate  is  a  cross  section  of  the  side  rail  showing  the  flange  on  the  bottom 
and  the  sleeve  of  the  tongue  and  sleeve  joint  which  is  used  to  connect 
the  side  rails,  end  to  end.  The  flexible  side  rails  are  used  to  form  curved 
sections  and  curves  of  6-inch  radius  for  intersections,  etc. 

Curb  forms  18  inches  high,  6  inches  on  top  with  a  batter  on  each 

side  consist  of  side  rails  and  templates.     The  templates  are  designed 

Curb  f  rm     w^n  ^u£s  f°rmmg  hooks  over  which  the  sidewalk  side  rail 

may  be  placed  with  the  flange  on  top.  The  top  of  these  templates 

is  rounded  to  a  2-inch  radius  on  each  side. 

Curb  and  gutter  forms  are  built  on  the  same  lines  as  the  curb  forms 

having  a  template  or  division  plate  shaped  to  the  section  of  a  6-inch 

curb  and  18-inch  gutter.    This  template  has  a  projection  to 

Cutt ' r"fd         hold  the  bottom  of  a  plank  or  face  form  in  place.    A  notch  in 

the  top  of  the  curb  templet  provides  for  the  use  of  a  hook  to 

hold  the  top  of  the  plank.    The  plank  has  one  edge  rounded  to  form  a 

curve  at  the  intersection  of  the  gutter  and  curb.    A  slotted  slug  is  used 

to  hold  the  side  rail  for  the  front  of  the  gutter. 


Universal    Portland     Cement     Co. 


The  Zeiser  steel  forms,  manufactured  by  Zeiser  Bros,  of  Berwick, 
Penna.,  are  composed  of  side  rails,  division  plates,  flexible  and  extension 
side  rails,  and  one-quarter  circle  curves.  The  side  rails  are  ^-inch  thick 
and  4  inches  high,  having  a  top  flange  of  2  inches  wide,  made  of 
Zeiser  Bros.  Open  hearth  cold  pressed  steel  channels  in  standard  lengths  of 
forms"  10  feet»  and  intermediate  lengths  of  4  and  6  feet.  A  tongue  and 
socket  is  used  to  join  the  rails  end  to  end.  Extension  side  rails  in 
\]/2,  2  and  3-foot  lengths  made  of  thinner  material  and  a  trifle  larger  than 
the  regular  side  rail,  are  provided.  These  side  rails  will  slide  over  the 
ends  of  the  regular  side  rails,  making  it  possible  to  work  out  any  length 
of  side  rail  that  may  be  desired,  and  are  useful  in  constructing  yard 
walks  or  short  sections  of  sidewalk  which  may  be  built  between  walks 
or  other  construction  work.  The  side  rails  are  slotted  at  intervals  of 
one  foot  apart  to  provide  for  ^  inch  steel  division  plates  or  templates, 
which  are  2  to  8  feet  long,  with  slotted  ends  to  form  hangers.  These 
drop  into  the  slot  in  the  side  rail,  as  indicated  in  Figure  86.  Dividing 
plates  are  equipped  with  an  auto- 
matic locking  device,  as  shown  in 
Figure  85  which  can  be  locked  and 
unlocked,  without  the  use  of  tools. 
Wooden  wedges  can  also  be  used  for 
locking  purposes  as  evidenced  by 
Figure  86.  The  %  inch  hole  shown 
near  the  end  is  provided  as  a  finger 
hold  to  be  used  in  removing  the  tem- 
plate. This  allows  the  division  plate 
to  be  removed  without  disturbing  the 
side  rails.  Quarter  circle  curves  of  6,  8  or  12-inch  radius  are  made,  4 
inches  high,  of  3/g-inch  steel  rail,  having  one  end  arranged  to  fit  in  the 


Figure  85 — Zeiser  division  plate  lock. 


Figure  86 — Zeiser  steel  sidewalk  forms. 


socket  of  the  side  rails.    These  curves   are  for   making   approaches  to 
steps,  joining  intersecting  walks,  etc. 

Division  plates  of  a  similar  type  are  made    to  be  used  with  2x4 
lumber,  where  such  are  desired. 

These  forms  are  all  coated  with  asphaltum  paint  to  prevent  rusting. 


('  one  ret  e     P  a  /•  e  m  e  n  1 s ,     <S  i  d  e  ir  a  I  k  s ,     Curb     and     Gutter 


Special  Tools 

Several  manufacturers  have  designed  special  tools 
work  which  may  be  of  interest  and  are  all  placed  upon 
the  idea  of  lightening  labor  or  decreasing 
expense. 

The  Andrews  Concrete  Tamper  is  manu- 
factured  by   Harold    L.   Bond    Company, 
383-391  Atlantic  Avenue,  Boston.  The  tam- 
per is  8  inches  square  divided  on 

Cowete"*   *!ie  face  with  Pryaniidal  projec- 

Tamper  tions    as    shown    in  Figure    87. 

The  projections    are   connected 

at  their  bases  in  such  a  way  as  to  prevent 

particles   of  stone  from  becoming  wedged 

between  them.     It  is  designed  to  displace 

the  stones  forming  a  part  of  the  top  layer 

of  concrete  with  mortar  so  as  to  permit  of 

finishing  the  surface  without  the  necessity 

of  applying  a  top  course. 

The  Arrowsmith  Concrete  Tool  Com- 
pany   of  Arrowsmith,  Illinois,  are    manu- 
facturers   of    the    long    handled    finishing- 
tools  illustrated  in  Figure  88, 
Arrowsmith          which  shows  a  15-inch  trowel, 
Long  Handled        „.    •      ,       .  >  . 

Finishing  Tools    24 -inch    trowel,    edger     and 
jointer  with  long  handles,  one 
pair  of  compasses,  an  interchangeable  short 
emergency  handle  and  wrench. 


for  the  concrete 
the  market  with 


Figure  87 — Andrews  concrete 


— Arrowsmith   long-handled  concrete  finishing 


The  trowel  blades  are 
made  of  21 -gauge  steel  at- 
tached to  a  malleable  iron 
T        ,   mounting.     The  long 
handle    is    connected 
directly    to   the    mounting 
and  can  be  adjusted  to  any 
angle  the  operator  may 
desire. 

The  edgers  and  jointers 
are  made  of  bronze  and 
malleable  iron  provided 
with  the  same  style  of 
handle  as  described  with 
the  trowel. 

These  are  molded  with  both 
Edger  and  edges  raised  to  aid 
jointer        in  securing  a  clean 
joint  and  edge. 


Univers  al    P  ort  land     Cement     Co. 


Compasses 


The   compasses   have   a   spread   of   6   feet.      When   closed 
the  guide  blade  lays  along  the  side  of  the  arm  like  the  blade 
of  a  pocket  knife,  thereby  taking  up  no  unnecessary  space. 

The  Concrete  Supply  Company,  Arrowsmith,  Illinois,  make 
The  Concrete  Supply  Co.'s  long  handled  trowels,  edgers,  groovers  and 
Long  Handled  Tools  tampers;  also  the  strike-off  shown  in  Figure  89. 


Figure  89 — Long  handled  concrete  finishing  tools,  manufactured  by  the  Concrete  Supply  Co. 


The  trowels  are  manufactured  in  20-inch  and  24-inch  lengths.    They 
are  made  of  tempered  steel  with  riveted  malleable  rib.     Each  trowel 
is  equipped  with  an  adjustable,  interchangeable  handle. 

The  edger  and  jointer  are  made  in  both  iron  and  bronze. 
These  tools  are  provided  with  an  adjustable  handle  similar  to  that  of 
the  trowel  and  have  a  rocker  shaped  face  which  prevents  the  point 

r,  _,  .  .   .      from  plowing  up  the  concrete  in  front.      By  the  use  of 

Eager  and  jointer     ,        .   \         ,,  te    .f  .    .  .     j^.    .  , 

short  handles  the  complete  set  is  converted  into  regular 

short -handled  tools. 

Compasses  are  made  of    malleable  iron,   highly  finished  with  the 
sides    channeled    out    to    cut    down    the    weight.      They    are   built   to 

.~  have  a  spread  of  any  width  up  to  six  feet,  and  are  intended 

Compasses      »  .  *  ,  "  ,  ,    r 

lor  use  in  laying  out  the  work. 

The  tamps  are  made  of  cast  iron  with  ll"xll"  face,  with  both 


Tamps 


plain  and  corrugated  bottoms.  The  corrugated  faces  are  intended 


to  avoid  the  suction  experienced  with  flat  bottomed  tools. 

The  Heltzel  Rotary  Float  shown  in  Figure  16,  consists  of  a  flat, 

round  disc-like  blade  attached  to  a  long  handle  by  means  of 

tary  Float    a   Jomt'    wmch    permits    operation    with    a    rotary    motion. 

The  blade  is  supplied  in  soft  wood  or  in  steel. 

The  finishing  trowel  shown   in  Figure   91   is   manufactured  by  the 
Twentieth  Century  Manufacturing  Company,  Chicago  Heights,  Illinois. 


aremcnts,     Side  tr  alks,     Curb    and    Gutter 


Figure  90 — Heltzel  Rotary  Float. 


Trowel 


Twentieth  Century    The  trowel  has  a  steel  blade  24  inches  long,  5  inches 
Long  Handled  Tools  wi(je>  attached  to  the  handle  by  means  of  a  tilt  motion 
device  for  raising  the 
edge  of  the  blade. 

As  the  workman 
pulls  the  trowel,  the 
forward  edge  is  auto- 
matically raised 
up  to  prevent 
the  edge  from  dig- 
ging into  the  mor- 
tar, then  as  the  work- 
man pushes  the 
trowel,  this  action  is 
reversed  and  the 
other  edge  of  the 
blade  is  raised.  The 
device  enables  the 
operator  to  do  the 
work  without  raising 
or  lowering  the 
handle. 


The  jointer  is  a  16- 


Jointer 


. 

.,  ..',,. 

the    Same    tilting 


Figu  re  91—  Automatic  finishing  trowel  made  by  the  Twentieth  Cen- 
tury  Manufacturing  Company. 


Universal    Portland     C  e  m  ent    Co 


Edger 


device  as  the  trowel.  A  joint  casting 
which  will  slip  on  and  fasten  to  the 
trowel  or  jointer  blade  is  of  the  proper 
design  to  cut  a  joint  of  the  correct  size 
and  shape. 

The  edger  has  a  blade  10  inches 
long  by  3^2  inches  wide,  and  is 
rounded  on  one  side  to  give  the  correct 
curve  to  the  edge. 

While  means  for  protecting  the  fresh- 
ly laid  concrete  cannot  be  classed  directly 
under  special  tools,  yet  the  appearance 
of  the  work  depends 

Lantern  holders  and      largely  upon  keeping 
woven  wire  standards     .      7e  i  •        i 

traffic     and    animals 

from  the  work  until  hardened.  The 
Anderson  Tool  and  Supply  Co.,  Detroit, 
Mich.,  makes  a  specialty  of  the  supports 
illustrated  in  Figure  92. 


Figure  92 — Lantern  and  wire  holders.. 


.J: 


Figure  93— An  inspection  party  starting  out  to  tour  the  concrete  roads  of  Wayne  County,  Michigan. 

—81— 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 


Proposed  Revised  Standard  Specifica- 
tions Concrete  Roads  and 
Street  Pavements 

Presented  to  the 

National  Association  of  Cement  Users 
December,  1912 

Materials 

1.  CEMENT.     The  cement  shall  meet  the  requirements  of  the  Stand- 
ard  Specifications  for  Testing  Materials,  and  adopted  by  this  Associ- 
ation (Standard  Xo.  1). 

2.  FIXE  AGGREGATE  FOR  CONCRETE.     Fine  aggregate  shall  consist 
of  sand,  crushed  stone  or  gravel  screenings  graded  from  fine  to  coarse 
and  passing  when  dry,  a  screen  having  one-quarter  (J4)  inch  diameter 
holes;  shall  be  preferably  of  silicious  material,  clean,  coarse,  free  from 
dust,  soft  particles,  loam,  vegetable  or  other  deleterious  matter,  and 
not  more  than  three  (3)  percent  shall  pass  a  sieve  having  one  hundred 
(100)  meshes  per  linear  inch.     Fine  aggregate  shall  be  of  such  quality 
that  mortar  composed  of  one  (1)  part  Portland  cement  and  three  (3) 
parts  fine  aggregate,  by  weight,  when  made  into  briquettes,  will  show  a 
tensile  strength  at  least  equal  to  the  strength  of  1 :3  mortar  of  the  same 
consistency  made  with  the  same  cement  and  Standard  Ottawa  sand. 
In  no   case  shall  fine  aggregate  containing  frost  or  lumps  of  frozen 
material  be  used. 

3.  AGGREGATE  FOR  WEARING  COURSE.     The  aggregate  shall  consist 
of  screened   gravel  or   stone    screenings    from  granite  or  other  close- 
grained  durable  rock,  sufficiently  hard  to  scratch  glass,  free  from  loam 
or  other  deleterious  matter,  mixed  in  the  proportion  of  three  (3)  parts 
passing  a  one-half  (J/0  inch  ring  and  retained  on  a  screen  having  one- 
quarter  (^)  inch  diameter  holes  and  two  (2)  parts  passing  a  screen 
having  one-quarter  (J^)  inch  diameter  holes  and  retained  on  a  screen 
having  fifty  (50)  meshes  per  linear  inch.     In  no  case  shall  aggregate  for 
wearing  course  containing  frost  or  lumps  of  frozen  material  be  used. 

4>.  COARSE  AGGREGATE  FOR  CONCRETE.  Coarse  aggregate  shall 
consist  of  inert  materials  such  as  stone  or  gravel,  graded  in  size,  retained 
on  a  screen  ha  ving  one-quarter  ( l/£)  inch  diameter  holes ;  shall  be  clean,  hard 
and  durable,  free  from  dust,  vegetable  or  other  deleterious  matter,  and 
shall  contain  no  soft,  flat  or  elongated  particles.  In  no  case  shall  coarse 
aggregate  containing  frost  or  lumps  of  frozen  material  be  used.  The 
maximum  size  of  the  coarse  aggregate  shall  be  such  as  to  pass  a  one 
and  one-half  (1^/2)  inch  ring. 

5.  NATURAL  MIXED  AGGREGATES.  Natural  mixed  aggregates  shall 
not  be  used  as  they  come  from  deposits,  but  shall  be  screened  and  remixed 
to  agree  with  the  proportions  specified. 


Universal    Portland     Cement    Co. 


6.  SUB-BASE.     Only  clean,   hard,   suitable  material,   not  exceeding 
four  (4)  inches  in  the  largest  dimensions,  shall  be  used. 

7.  WATER.     Water   shall   be   clean,   free   from   oil,   acid,    alkali,   or 
vegetable  matter. 

8.  COLORING.     If  artificial  coloring  matter  is  required,  only  mineral 
colors  shall  be  used. 

9.  REINFORCING    METAL.     The   reinforcing   metal    shall    meet   the 
requirements  of  the  Standard  Specifications  for  Steel   Reinforcement 
adopted  March  16,  1910  by  the  American  Railway  Engineering  Associa- 
tion. 

Sub-Grade 

10.  SECTION.     The  sub-grade  shall  have  a  rise  at  the  center  of  not 
more  than  one-hundredth  (1-100)  the  width  of  the  pavement. 

11.  DEPTH,     (a)  The  sub-grade  shall  not  be  less  than  twelve  (12) 
inches  below  the  finished  surface  of  the  pavement. 

(b)  The  sub-grade  shall  not  be  less  than  six  (6)  inches  below  the 
finished  surface  of  the  pavement. 

12.  PREPARATION.     All  soft  and  spongy  places  shall  be  removed  and 
all  depressions  filled  with  suitable  material  which  shall  be  thoroughly 
compacted  in  layers  not  exceeding  six  (6)  inches  in  thickness. 

13.  DEEP  FILLS.     When  a  fill  exceeding  one  (1)  foot  in  thickness  is 
required  to  bring  the  pavement  to  grade,  it  shall  be  made  in  a  manner 
satisfactory  to  the  engineer. 

14.  DRAINAGE.     When  required,  a  suitable  drainage  system  shall  be 
installed  and  connected  with  sewers  or  other  drains  indicated  by  the 
engineer. 

NOTE. — When  a  sub-base  is  required,  eliminate  Paragraph  11-b.     When  sub-base  is  not  required, 
eliminate  Paragraphs  6,  11-a,  15  and  16.     Unless  11-a  is  eliminated,  11-b  is  void. 

15.  THICKNESS.     On  the  sub-grade  shall  be  spread  a  material  as 
hereinbefore  specified,  wrhich  shall  be  thoroughly  rolled  and  tamped  to  a 
surface  at  least  six  (6)  inches  below  the  finished  grade   of    the   pave- 
ment. 

16.  WETTING.     While  compacting  the  sub-base,  the  material  shall 
be  kept  thoroughly  wet  and  shall  be  in  that  condition  when  the  concrete 
is  deposited. 

Forms 

17.  MATERIALS.     Forms  shall  be  free  from  warp  and  of  sufficient 
strength  to  resist  springing  out  of  shape. 

18.  SETTING.     The  forms  shall  be  well  staked  or  otherwise    held 
to  the  established  lines   and    grades  and  their  upper  edges  shall  con- 
form to  the  established  grade  of  the  pavement. 

19.  TREATMENT.     All  wood  forms  shall  be  thoroughly  wetted  and 
metal  forms  oiled  before  depositing  any  material  against  them.     All 
mortar  and  dirt  shall  be  removed  from  forms  that  have  been  previously 
used. 

Expansion  Joints 

20.  WIDTH  AND  LOCATION.     Expansion  joints  not  less  than  one- 
quarter  (34)  inch  nor  more  than  one-half  (£^)  inch  in  width  shall  be 


Concrete     Pavements,     <S  ide walks,     Curb    and    Gutter 

placed  across  the  street  or  road,  not  more  than  twenty-five  (25)  feet 
apart.  When  a  curb  or  combination  curb  and  gutter  is  used  a  one-half 
inch  (}/%)  joint  shall  be  placed  between  it  and  the  pavement.  All  expan- 
sion joints  shall  extend  through  the  entire  thickness  of  the  pavement. 

21.  JOINT  FILLER.     The  expansion  joint  filler  for  open  joints  shall 
be  a  suitable  bitumen  that  will  not  become  soft  in  hot  weather  nor  hard 
and  brittle  in  cold  weather.     Expansion  joints  may  also  be  formed  by 
inserting  during  construction  and  leaving  in  place  a  total  thickness  of 
one-quarter  (34)  mcn  of  tarred  paper  or  tarred  felt. 

22.  PROTECTION   OF   EDGES.     When   required   by   the   engineer   in 
charge,   the  concrete  at  the  expansion  joints  shall  be  protected  with 
metal.     Unless  protected  by  metal  or  filled  with  tarred  paper  or  felt,  the 
upper  edges  of  the  concrete  shall  be  rounded  to  a  radius  of  three-eights 
(%)  inch. 

Measuring  and  Mixing 

23.  MEASURING.     The  method  of  measuring  the  materials  for  the 
concrete,  including  water,  shall  be  one  which  will  insure  separate  uniform 
proportions    at    all    times.      A   sack   of    Portland   cement    (94  pounds 
net)  shall  be  considered  one  (1)  cubic  foot. 

24.  MACHINE  MIXING.     When  the  conditions  will  permit,  a  machine 
mixer  of  a  type  which  insures  the  uniform  proportion  of  the  materials 
throughout  the  mass,  shall  be  used.     The  ingredients  of   the  concrete 
or  mortar  shall  be  mixed  to    the    desired  consistency  and  the  mixing 
shall  continue  until  the  cement  is  uniformly  distributed  and  the  mass  is 
uniform  in  color  and  homogeneous. 

25.  HAND   MIXING.     When  it  is   necessary   to   mix  by  hand,   the 
materials  shall  be  mixed  dry  on  a  water-tight  platform  until  the  mixture 
is  of  uniform  color,  the  required  amount  of  water  added,  and  the  mixing 
continued  until  the  mass  is  of  uniform  color  and  homogeneous. 

26.  RETEMPERING.     Retempering,  that  is,  remixing  mortar  or  con- 
concrete  that  has  partially  hardened,  with  additional  water,  will  not  be 
permitted. 

Two-Course  Pavement 

Base 

27.  PROPORTIONS.     The  concrete  shall  be  mixed  in  the  proportion 
of  one  (1)  sack  Portland  cement,  two  and  one-half  (23^)  cubic  feet  fine 
aggregate,  and  five  (5)  cubic  feet  coarse  aggregate. 

28.  CONSISTENCY.     The   materials   shall   be   mixed   with   sufficient 
water  to  produce  a  concrete  of  a  consistency  such  that  mortar  will  flush 
to  the  surface  under  light  tamping,  but  which  can  be  handled  without 
causing  a  separation  of  the  coarse  aggregate  from  the  mortar. 

29.  PLACING.     After  mixing,  the  concrete  shall  be  handled  rapidly 
into  place  and  successive  batches  deposited  in  a  continuous  operation, 
completing  sections  between  expansion  joints  without  the  use  of  inter- 
mediate cross  forms  or  bulk  heads.    Concrete  shall  not  be  used  that  has 
partially  hardened.    The  concrete  shall  be  well  tamped  to  a  surface  the 
thickness  of  the  wearing  surface  below  the  established  grade  of  the  pave- 
ment.   Workmen  shall  not  walk  on  freshly  laid  concrete,  and  if  sand  or 


Universal    Portland    Cement     Co. 


dust  collects  on  the  base,  it  shall  be  removed  before  the  wearing  course 
is  applied. 

30.  REINFORCING.      On  streets  more   than   twenty    (20)    feet  wide 
not   having  car  tracks,   the  pavement  shall   be  reinforced   with    wire 
fabric  or  with  plain  or  deformed  bars.     The  cross  sectional  area  of 
metal  shall  amount  to  at  least  0.041  square  inches  per  foot  measured 
parallel  to  the  axis  of  the  street,  and  at  least  0.025  square  inches  per 
foot  measured  perpendicular  to  the  axis  of  the  street.     The  reinforcing 
metal  shall  be  placed  upon  and  slightly  pressed  into  the  concrete  base 
immediately  after  the  base  is  placed.     Reinforcing  metal  shall  not  cross 
expansion  joints  and  shall  be  lapped  sufficiently  to  develop  the  strength 
of  the  metal. 

Wearing  Course 

31.  PROPORTIONS.     The    mortar    shall    be    mixed    in    the    manner 
hereinbefore  specified  in  the  proportion  of  one  (1)  sack  Portland  cement 
and  not  more  than  (2)  cubic  feet  of  aggregate  for  wearing  course. 

32.  CONSISTENCY.     The    mortar    shall    be    of    a    consistency    that 
will  not  require  tamping  but  which  can  be  easily  spread  into   position 
with  a  template  or  straight  edge. 

33.  THICKNESS.     The  wearing  course  of  the  pavement  in  residence 
districts  shall  have  a  minimum  thickness  of  one  and  one-half   (1^2) 
inches,  and  in  business  districts  a  minimum  of  two  (2)  inches  in  thickness. 

34.  PLACING.     The  wearing  course  shall  be  placed  immediately  after 
mixing,  and  in  no  case  shall  more  than  fifty  (50)  minutes  elapse  between 
the  time  the  concrete  for  the  base  is  mixed  and  the  time  the  wearing 
course  is  placed. 

35.  FINISHING.     After  the  wearing  course  has  been  brought  to  the 
established  grade  with  a  template  or  straight  edge,  it  shall  be  worked 
with  a  wood  float  in  a  manner  to  thoroughly  compact  it  and  produce  a 
comparatively  smooth  surface,  free  from  depressions  or  inequalities  of 
any  kind.     Tne  finished  surface  of  the  concrete  shall  not  vary  more 
than  one-quarter  (%)  inch  from  a  two  (2)  foot  straight  edge  placed  upon 
the  concrete  in  any  position. 

36.  COLORING.     If  artificial  coloring  is  used,  it  must  be  incorporated 
with  the  entire  wearing  course  and  shall  be  mixed  dry  with  the  cement 
and  aggregate  until  the  mixture  is  of  uniform  color.     In  no  case  shall 
the  amount  of  coloring  used  exceed  five  (5)  percent  of  the  weight  of 
the  cement. 

One-Course  Pavement 

The  general  requirements  of  the  specifications  covering  two-course 
work  will  apply  to  one-course  work  with  the  following  exceptions: 

37.  PROPORTIONS.     The  concrete  shall  be  mixed  in  the  proportion 
of  one  (1)  sack  Portland  cement  to  not  more  than  two  (2)  cubic  feet 
of  fine  aggregate   (paragraph  2)   or  aggregate  for  wearing  course  (par- 
agraph  3)    and   three    (3)    cubic   feet   of    coarse    aggregate   passing    a 
one  (1)  inch  ring. 

38.  PLACING  AND  FINISHING.     The  concrete  shall  be  placed  and  fin- 
ished  as   provided  for   under   "Two -Course  Pavement,"   "Base"   and 
"Wearing  Course"  respectively. 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 

39.  REINFORCING.     When    a    one-course    pavement   is    reinforced, 
the  metal  shall  be  placed  at  the  middle  of  the  section.     The  minimum 
amount  of  metal  shall  be  as  specified  under  "Two-Course  Pavement." 

Crown 

40.  AMOUNT.     All  types  of  concrete  pavement  shall  be  given  a  rise 
or  crown  at  the  center  of  at  least  one-hundredth  (1-100)  but  not  more 
than  one-seventy-fifth  (1-75)  of  the  width  of  the  pavement.    A  portion 
of  this  crown  may  be  obtained  by  increasing  the  thickness  of  the  pave- 
ment at  the  center  rather  than  by  laying  a  pavement  of  uniform  thick- 
ness on  a  crowned  sub-grade  or  sub-base. 

Protection 

41.  TREATMENT.     As  soon  as  the  concrete  has  hardened  sufficiently  to 
prevent  being  pitted,  the  surface  of  the  pavement  shall  be  sprinkled  with 
clean  water  and  shall  be  kept  wet  for  at  least  four  (4)  days.     Concrete 
pavement  on  roads  shall  be  covered  as  soon  after  finishing  as  it  is  possible 
to  do  so  without  damaging  the  surface,  with  at  least  two  (2)  inches  of 
dirt  which  shall  be  kept  wet  for  at  least  four  (4)  days.    Before  covering 
with  dirt,  the  pavement  shall  be  sprinkled  with  water  as  above  specified. 
The  pavement  shall  not  be  open  to  traffic  until  the  engineer  so  directs. 

42.  TEMPERATURE  BELOW  35°  FAHR.     If  at  any  time  during  the 
progress  of  the  work  the  temperature  is,  or  in  the  opinion  of  the  engineer 
will,  within  24  hours  drop  to  thirty-five  (35)  degrees  Fahrenheit,  the 
water  and  aggregates  shall  be  heated  and  precautions  taken  to  protect 
the  work  from  freezing  for  at  least  five  (5)  days.    In  no  case  shall  con- 
crete be  deposited  upon  a  frozen  sub-grade  or  sub-base. 

Shoulders 

43.  CONSTRUCTION.     On  streets  where  the  pavement  does  not  occupy 
the  full  width  of  the  street,  and  on  roads,  a  gravel  or  crushed  stone 
shoulder  at  least  two  (2)  feet  wide  shall  be  constructed  on  each  side  of 
the  pavement.     The  surface  of  the  shoulders  shall  have  a  slope  away 
from  the  pavement  of  one  and  one-half  (1^)  inches  per  foot,  and  a 
thickness  for  the  two  (2)  foot  width  adjoining  the  concrete,  at  least 
equal  to  the  minimum  thickness  of  the  concrete. 

Wearing  Surface  Bitumen  and  Fine  Aggregate 

44.  CONSTRUCTION.     Where  a  wearing  surface  of  bitumen  and  fine 
aggregate  is  used,  it  shall  preferably  be  placed  upon  a  one-course  pave- 
ment, constructed  as  hereinbefore  specified,  but  may  be  used  also  on 
two-course  work. 

45.  EXPANSION  JOINTS.     Before  applying  the  bitumen  to  the  con- 
crete, all  open  expansion  joints  shall  be  filled  as  hereinbefore  specified. 
Where  required  by  the  engineer  in  charge,  concrete  at  the  expansion 
joints  shall  be  protected  with  metal. 

46.  BITUMEN.     The  bitumen  shall  be  of  a  quality  specified  by  the 
engineer. 

47.  PLACING  WEARING  SURFACE.     After  the  concrete  has  hardened 
for  at  least  seven  (7)  days  the  thoroughly  cleaned  dry  surface  of  the 


Universal    Portland    Cement    Co. 


pavement  shall  be  covered  with  hot  bitumen  applied  with  a  sprinkling 
wagon  designed  for  the  purpose,  or  with  suitable  hand  sprinkling  cans. 
The  hot  bitumen  shall  immediately  be  evenly  distributed  over  the  con- 
crete by  brushing  with  suitable  brooms  and  then  covered  with  the 
required  amount  of  fine  aggregate  (paragraph  3). 

48.  AMOUNT  OF  BITUMEN  AND  FINE  AGGREGATE.     Approximately 
one-half  (^2)   gallon  of  bitumen  shall  be  applied  per  square  yard  of 
pavement  and  approximately  one  (1)  cubic  yard  of  fine  aggregate  shall 
be  applied  per  one  hundred  and  fifty  (150)  square  yards  of  pavement. 

Protection 

49.  OPEN  TO  TRAFFIC.     The  pavement  shall  not  be  open  to  traffic 
until  the  engineer  so  directs. 


Specifications  for  Portland  Cement 
Sidewalks 

Presented  to  the 

National  Association  of  Cement  Users, 
December,  1912 

Materials 

1.  CEMENT.     The  cement  shall  meet  the  requirements  of  the  Stan- 
dard Specifications  for  Portland  Cement  of  the  American  Society  for  Test- 
ing Materials  and  adopted  by  this  Association.     (Standard  No.  1.) 

2.  FINE  AGGREGATE.     Fine  aggregate  shall  consist  of  sand,  crushed 
stone  or  gravel  screenings,  graded  from  fine  to  coarse  and  passing  when 
dry  a  screen  having  one-quarter  (^)  inch  diameter  holes;  shall  be  pre- 
ferably of  silicious  material,  clean,  coarse,  free  from  dust,  soft  particles, 
loam,  vegetable  or  other  deleterious  matter,  and  not  more  than  three  (3) 
per  cent  shall  pass  a  sieve  having  one  hundred  (100)  meshes  per  linear 
inch.    Fine  Aggregate  shall  be  of  such  quality  that  mortar  composed  of 
one  part  Portland  Cement  and  three  (3)  parts  fine  aggregate  by  weight, 
when  made  into  briquettes  will  show  a  tensile  strength  at  least  equal  to 
the  strength  of  1 :3  mortar  of  the  same  consistency  made  with  the  same 
cement  and  Standard  Ottawa  sand.     In  no  case  shall  fine  aggregate 
containing  frost  or  lumps  of  frozen  material  be  used. 

3.  COARSE   AGGREGATE.     Coarse   aggregate   shall   consist   of   inert 
materials  such  as  crushed  stone  or  gravel,  graded  in  size,  retained  on  a 
screen  having  one-quarter  (J^)  inch  diameter  holes;  shall  be  clean,  hard 
and  durable;  free  from  dust,  vegetable  or  other  deleterious  matter,  and 
shall  contain  no  soft,  flat  or  elongated  particles.    In  no  case  shall  coarse 
aggregate  containing  frost  or  lumps  of  frozen  material  be  used.     The 
maximum  size  of  coarse  aggregate  shall  be  such  as  to  pass  a  one  and 
one-quarter  (1^)  mch  ring. 

4.  NATURAL  MIXED  AGGREGATES.     Natural  mixed  aggregates  shall 
not  be  used  as  they  come  from  the  deposit,  but  shall  be  screened  and 
remixed  to  agree  with  the  proportions  specified. 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 

5.  SUM-BASE.  Only  clean,  hard  suitable  material,  not  exceeding 
four  (4)  inches  in  the  largest  dimension  shall  be  used. 

0.  WATER.  Water  shall  be  clean,  free  from  oil,  acid,  alkali  or 
vegetable  matter. 

7.  COLORING.     If  artifical  coloring  material  is  required  only  mineral 
colors  shall  be  used. 

8.  REINFORCING  METAL.     The  reinforcing  metal  shall  meet  the  re- 
quirements of  the  Standard  Specifications  for  Steel  Reinfocement  adopt- 
ed March  16,1910,  by  the  American  Railway   Engineering  Association. 

Sub -Grade 

9.  SLOPE.     The  sub-grade  shall  have  a  slope  toward  the  curb  of 
not  less  than  one-half  (^)  inch  per  foot. 

10.  DEPTH.*     (a)    The    sub-grade    shall    not    be  less  than   eleven 
(11)  inches  below  the  finished  surface  of  the  walk. 

(b)  The  sub-grade  shall  not  be  less  than  five  (5)  inches  below  the 
finished  surface  of  the  walk. 

11.  PREPARATION.     All  soft  and  spongy  places  shall  be  removed  and 
all  depressions  filled  with  suitable  material  which  shall  be  thoroughly 
compacted  in  layers  not  exceeding  six  (6)  inches  in  thickness. 

12.  DEEP  FILLS.     When  a  fill  exceeding  one  (1)  foot  in  thickness  is 
required  to  bring  the  work  to  grade,  it  shall  be  made  in  a  manner  satis- 
factory to  the  engineer.     The  top  of  all  fills  shall  extend  beyond  the 
walk  on  each  side  at  least  on  (1)  foot,  and  the  sides  shall  have  a  slope 
not  greater  than  one  (1)  to  one  and  one-half  (l}/£). 

13.  DRAINAGE.     When    required,   a  suitable  drainage  system  shall 
be  installed  and  connected  with  sewers  or  other  drains  indicated  by 
the  engineer. 

Sub- Base* 

14.  WTIDTH — THICKNESS.     On    the    sub-grade    shall    be    spread    a 
suitable    material    as    hereinbefore    stated    which    shall    be    thoroughly 
rolled  or  tamped  to  a  surface  at  least  five  (5)  inches  below  the  finished 
grade  of   the   walk.     On   the  fills,   the  sub-base   shall  extend  the  full 
width  of  the  fill  and  the  sides  shall  have  the  same  slope  as  the  sides  of 
the  fill. 

15.  WETTING.     While  compacting  the  sub-base,  the  material  shall 
be  kept  thoroughly  wet  and  shall  be  in  that  condition  when  the  concrete 
is  deposited. 

Form* 

16.  MATERIALS.     Forms  shall  be  free  from  warp  and  of  sufficient 
strength  to  resist  springing  out  of  shape. 

17.  SETTING.     The  forms  shall   be  well   staked  or  otherwise  held 
to  the  established  lines  and  grades  and  their  upper  edges  shall  con- 
form to  the  established  grade  of  the  walk. 

18.  TREATMENT.     All  wood  forms  shall  be  thoroughly  wetted  and 
metal  forms  oiled  before  depositing  any  material  against  them.     All 
mortar  and  dirt  shall  be  removed  from  forms  that  have  been  previously 
used. 

*NOTE. — When  a  sub-base  is  required,  eliminate  Paragraph  10 (b).  When  a  sub-base  is  not  required 
eliminate  Paragraphs  5  and  10(a).  Unless  Paragraph  10(a)  is  eliminated.  10(b)  is  void. 


Universal    Portland    Cement    Co. 


Construction 

19.  SIZE    OF   SLABS.     The   slabs   or   independently    divided    blocks 
when  not  reinforced  shall  have  an  area  of  not  more  than  thirty-six  (36) 
square  feet  and  shall  not  have  any  dimension  greater  than  six  (6)  feet. 
Larger  slabs  shall  be  reinforced  as  hereinafter  specified. 

20.  THICKNESS  OF  WALK.     The  thickness  of  the  walks  should  not 
be  less  than  five  (5)  inches  for  residence  districts,  and  not  less  than 
six  (6)  inches  for  business  districts. 

21.  WIDTH  AND  LOCATION  OF  JOINTS.     A  one-half  (^)  inch  expan- 
sion joint  shall  be  provided  at  least  orce  in  every  fifty  (50)  feet. 

22.  JOINT  FILLING.     The  expansion  joint  filler  shall  be  a  suitable 
elastic  waterproof  compound  that  will  not  become  soft  and  run  out  in 
hot  weather,  nor  hard  and  brittle  and  chip  out  in  cold  weather. 

23.  PROTECTION   OF   EDGES.     Unless  protected  by  metal,  the  upper 
edges  of  the  concrete  shall  be  rounded  to   a   radius   of   one-half    (^) 
inch. 

Measuring  and  Mixing 

24.  MEASURING.     The  method  of  measuring  the  materials  for  the 
concrete,  including  water,  shall  be  one  which  will  insure  separate  uniform 
proportions  at  all  times.     A  sack  of  Portland  cement  (94  Ib.  net)  shall 
be  considered  one  (1)  cubic  foot. 

25.  MACHINE  MIXING.     When  the  conditions  will  permit,  a  machine 
mixer  of  the  type  that  insures  the  uniform  proportioning  of  the  materials 
throughout  the  mass,  shall  be  used.    The  ingredients  of  the  concrete  or 
mortar  shall  be  mixed  to  the  desired  consistency  and  the  mixing  shall 
continue  until  the  cement  is  uniformly  distributed  and  the  mass  is  uni- 
form in  color  and  homogeneous. 

26.  HAND  MIXING.     When  it  is  necessary  to  mix  by  hand,  the  mate- 
rials shall  be  mixed  dry  on  a  watertight  platform  until  the  mixture  is  of 
uniform  color,  the  required  amount  of  water  added  and  the  mixing  con- 
tinued until  the  mass  is  uniform  in  color  and  homogeneous. 

27.  RETEMPERING,  that   is,    remixing  mortar  or  concrete  that  has 
partially  hardened  with  additional  water,  will  not  be  permitted. 

Two-Course  Walks 

Base 

28.  PROPORTIONS.     The  concrete  shall  be  mixed  in  the  proportion 
by  volume  of  one  (1)  sack  Portland  cement,  two  and  one-half  (2}/£) 
cubic  feet  fine  aggregate  and  five  (5)  cubic  feet  coarse  aggregate. 

29.  CONSISTENCY.     The    materials    shall   be    mixed  wet  enough  to 
produce  a  concrete  of  a  consistency  that  wrill  flush  readily  under  slight 
tamping,  but  which  can  be  handled  without  causing  a  separation  of  the 
coarse  aggregate  from  the  mortar. 

30.  PLACING.     After  mixing,  the  concrete  shall  be  handled  rapidly 
and  the  successive  batches  deposited  in  a  continuous  operation  com- 
pleting individual  sections.     Under  no  circumstances  shall  concrete  be 
used  that  has  partially  hardened.     The  forms  shall  be  filled  and  the 
concrete  struck  off  and  tamped  to  a  surface  the  thickness  of  the  wearing 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 

course  below  the  established  grade  of  the  walk.  After  the  concrete  has 
been  thoroughly  tamped  against  the  cross  forms,  they  shall  be  removed 
and  the  material  for  the  adjoining  slab  deposited  so  as  to  preserve  the 
joint.  Workmen  shall  not  be  permitted  to  walk  on  the  freshly  laid 
concrete,  and  if  sand  or  dust  collects  on  the  base  it  shall  be  carefully 
removed  before  the  wearing  course  is  applied. 

31.  REINFORCEING.     Slabs   having  an   area  of    more  than   thirty- 
six  (36)  square  feet,  or   having    any    dimension   greater   than   six    (6) 
feet,  shall  be  reinforced  with   wire  fabric  or  with   plain   or   deformed 
bars.      The  cross  sectional  area  of  metal  shall  amount  to  at  least  0.041 
sq.  in.  per  lin.  ft.     The  reinforcing   metal  shall    be    placed    upon    and 
slightly    pressed    into    the    concrete    base   immediately  after  the  base 
is  placed.     Reinforcing  metal  shall  not  cross  joints  and  shall  be  lapped 
sufficiently  to  develop  the  strength  of  the  metal. 

Wearing  Course 

32.  PROPORTIONS.     The    mortar    shall    be    mixed    in    the    manner 
hereinbefore    specified    in    the    proportion    of   one    (1)    sack    Portland 
cement,   and  not  more  than  two   (2)    cubic   feet  of   fine  aggregate. 

33.  CONSISTENCY.     The  mortar  shall  be  of  a  consistency  that  will 
not  require  tamping,  but  which  can  be  easily  spread  into  position. 

34.  THICKNESS.     The    wearing    course    of    the    walk    in    residence 
districts  shall  have  a  minimum  thickness  of  three-quarters  (%)  of  an 
inch,  and  in  business  districts  a  minimum  thickness  of  one  (1)  inch. 

35.  PLACING.     The    wearing   course    shall    be   placed    immediately 
after  mixing  and  in  no  case  shall  more  than  fifty  (50)  minutes  elapse 
between  the  time  the  concrete  for  the  base  is  mixed  and  the  time  the 
wearing  course  is  placed. 

36.  FINISHING.     After  the  wearing  course  has  been  brought  to  the 
established  grade,  it  shall  be  worked  with  a  wood  float  in  a  manner  that 
will  thoroughly  compact  it.    When  required,  the  surface  shall  be  troweled 
smooth,  but  excessive  working  with  a  steel  trowel  should  be  avoided. 
The  slab  markings  shall  be  made  in  the  wearing  course  directly  over  the 
joints  in  the  base  with  a  tool  which  will  completely  separate  the  wearing 
course  of  adjacent  slabs.     If  excessive  moisture  occurs  on  the  surface, 
it  must  be  taken  up  with  a  rag  or  mop  and  in  no  case  shall  dry  cement  or 
a  mixture  of  dry  cement  and  sand  be  used  to  absorb  this  moisture  or 
to  hasten  the  hardening.     Unless  protected  by  metal,  the  surface  edges 
of  all  slabs  shall  be  rounded  to  a  radius  of  about  one-half  Q/z)  inch. 

37.  COLORING.     If  artificial  coloring  is  used,  it  must  be  incorpor- 
ated with  the  entire  wearing  course  and  shall  be  mixed  dry  with  the 
cement  and  aggregate   until   the   mixture   is   of   uniform  color.     In  no 
case  shall  the  amount  of  coloring  used  exceed  five  (5)  percent  of   the 
weight  of  the  cement. 

One- Course  Walk 

The  general  requirements  of  the  specifications  covering  two-course 
work  will  apply    to    one-course  work  with  the   following  exceptions: 


Universal    Portland     Cement     Co. 


38.  PROPORTIONS.     The  concrete  shall  be  mixed  in  the  proportion  of 
one  (1)  sack  Portland  cement  to  not  more  than  two  (2)  cubic  feet  of  fine 
aggregate,  and  three  (3)  cubic  feet  of  coarse  aggregate  passing  a  one  (1) 
inch  ring. 

39.  PLACING  AND  FINISHING.     The  form  shall  be  filled,  the  concrete 
struck  off  and  the  coarse  particles  forced  back  from  the  surface,  and  the 
work  finished  in  the  usual  way. 

40.  REINFORCING.     When  a  single  course  walk  is  to  be  reinforced, 
the  metal  shall  be  placed  at  the  middle  of  the  section.     The  minimum 
amount  of  metal  shall  be  as  specified  in  paragraph  thirty -one  (31). 

Protection 

41.  TREATMENT.     As  soon  as  the  concrete  has  hardened  sufficiently 
to  prevent  being  pitted  the  surface  of  the  walk  shall  be  sprinkled  with 
clean  water  and  kept  wet  for  at  least  four  (4)  days.    The  walk  shall  not 
be  opened  to  traffic  until  the  engineer  so  directs. 

42.  TEMPERATURE  BELOW  35°  F.     If  at  any  time  during  the  pro- 
gress of  the  work  the  temperature  is,  or  in  the  opinion  of  the  engineer 
will   within   twenty-four    (24)    hours   drop   to   thirty-five    (35)    degrees 
Fahrenheit,  the  water  and  aggregates  shall  be  heated  and  precautions 
taken  to  protect  the  work  from  freezing  for  at  least  five  (5)  days.     In 
no  case  shall  concrete  be  deposited  upon  a  frozen  sub-grade  or  sub-base. 


Concrete    Pavements,     Sidewalks,     Curb    and    Gutter 


Proposed  Revised  Standard  Specifica- 
tions for  Concrete  Curb 
and  Concrete  Curb  and  Gutter 

Presented  to  the 

National  Association  of  Cement  Users 
December,  1912 

Materials 

1.  CEMENT.     The  cement  shall  meet  the  requirements  of  the  Stand- 
ard Specifications  for  Portland   Cement  of  the  American  Society  for 
Testing  Materials  and  adopted  by  this  Association.     (Standard  No.  1) 

2.  FIXE  AGGREGATE.     Fine  aggregate  shall  consist  of  sand,  crushed 
stone  or  gravel  screenings,  graded  from  fine  to  coarse  and  passing  when 
dry  a  screen  having  one-quarter  (%)  inch  diameter  holes;  shall  be  pre- 
ferably of  silicious  material,  clean,  coarse,  free  from  dust,  soft  particles, 
loam,  vegetable  or  other  deleterious  matter  and  not  more  than  three  (3) 
percent  shall  pass  a  sieve  having  one  hundred  (100)  meshes  per  linear 
inch.     Fine  aggregate  shall  be  of  such  quality  that  mortar  composed  of 
one  part  Portland  cement  and  three  (3)  parts  fine  aggregate  by  weight 
when  made  into  briquettes  will  show  a  tensile  strength  at  least  equal 
to  the  strength  of  1 :3  mortar  of  the  same  consistency  made  with  the 
same  cement  and  Standard  Ottawa  sand.    In  no  case  shall  fine  aggregate 
containing  frost  or  lumps  of  frozen  material  be  used. 

3.  COARSE   AGGREGATE.     Coarse   aggregate   shall   consist   of   inert 
materials  such  as  crushed  stone  or  gravel  graded  in  size,  retained  on  a 
screen  having  one  quarter  (^)  inch  diameter  holes;  shall  be  clean,  hard 
and  durable,  free  from  dust  vegetable  or  other  deleterious  matter,  and 
shall  contain  no  soft,  flat  or  elongated  particles.    In  no  case  shall  coarse 
aggregate  containing  frost  or  lumps  of  frozen  material  be  used.     The 
maximum  size  of  coarse  aggregate  shall  be  such  as  to  pass  a  one  and  one- 
quarter  (1M)  mcn  ring- 

4.  NATURAL  MIXED  AGGREGATES.     Natural  mixed  aggregates  shall 
not  be  used  as  they  come  from  the  deposit,  but  shall  be  screened  and 
remixed  to  agree  with  the  proportions  specified. 

5.  SUB-BASE.     Only  clean,  hard,  suitable  materials,  not  exceeding 
four  (4)  inches  in  the  largest  dimension  shall  be  used. 

6.  WATER.     Water  shall  be  clean,  free  from  oil,  acid,  alkali  or  vege- 
table matter. 

7.  COLORING.     If  artificial  coloring  material  is  required  only  mineral 
colors  shall  be  used. 

Sub -Grade 

8.  DEPTH    BELOW    GRADE,     (a)  CONCRETE    CURB.     When    a    sub- 
base  is  required,  the  sub-grade  shall  not  be  less  than  thirty  (30)  inches 
below  the  established  grade  of  the  curb. 


Universal    Portland     Cement    Co. 


(b)  CONCRETE  CURB  AND  GUTTER.  When  a  sub-base  is  required, 
the  sub-grade  shall  not  be  less  than  eleven  (11)  inches  below  the  estab- 
lished grade  of  the  gutter. 

9.  PREPARATION.     All  soft  and  spongy  places  shall  be  removed  and 
all  depressions  filled  with  suitable  material  which  shall  be  thoroughly 
compacted  in  layers  not  exceeding  six  (6)  inches  in  thickness. 

10.  DEEP  FILLS.     When  a  fill  exceeding  one  (1)  foot  in  thickness  is 
required  to  bring  the  work  to  grade,  it  shall  be  made  in  a  manner  satis- 
factory to  the  engineer. 

1 1 .  DRAINAGE.    When  required,  a  suitable  drainage  system  shall  be  in- 
stalled and  connected  with  sewers  or  other  drains  indicated  by  the  engineer. 

Sub -Base 

12.  THICKNESS,     (a)  CONCRETE  CURB.     On  the  sub-grade  shall  be 
spread  a  material  as  hereinbefore  specified,  which  shall  be  thoroughly 
rolled  or  tamped  to  a  surface  at   least   twenty-four  (24)  inches    below 
the  established  grade  of  the  curb. 

(b)  CONCRETE  CURB  AND  GUTTER.  On  the  sub-grade  shall  be 
spread  a  material  as  hereinbefore  specified,  which  shall  be  thoroughly 
rolled  or  tamped  to  a  surface  at  least  six  (6)  inches  below  the  established 
grade  of  the  gutter. 

13.  WETTING.     While  compacting  the  sub-base,  the  material  shall 
be  kept  thoroughly  wet  and  shall  be  in  that  condition  when  the  concrete 
is  deposited. 

Forms 

14.  MATERIALS.     Forms  shall   be   free   from  warp  and  of  sufficient 
strength  to  resist  springing  out  of  shape. 

15.  SETTING.     The  forms  shall  be  well  staked  or  otherwise  held  to 
the  established  lines  and  grades,  and  their  upper  edges  shall  conform  to 
the  established  grade  of  the  curb  or  curb  and  gutter. 

16.  TREATMENT.     All  wood  forms  shall  be  thoroughly  wetted  and 
metal  forms  oiled  before  depositing  any  material  against  them.     All 
mortar   and   dirt   shall   be   removed   from   forms   that  have  been  pre- 
viously used. 

Construction 

17.  DIMENSION  OF  CURB.     The  section  of  the  curb  shall  conform 
with    that   shown    in   Fig.    1.     The  thickness  at  the  base  shall  not  be 
less  than  twelve  (12)  inches,    and    at   the   top    not    more  than  six  (6) 
inches  with  a  batter  on  the  street  side  of  one  (1)  to  four  (4). 

18.  DIMENSIONS  OF  CURB  AND  GUTTER.     The  sections  of  the  com- 
bination curb  and  gutter  shall  conform  with  that  shown  in  Figure    2. 
The  depth  of  the  back  of  the  curb  shall  not  be  less  than  twelve  (12) 
inches  and  the  depth  of  the  face  not  less  than  six  (6)  inches.  The  breadth 
of  the  gutter  shall  not  be  less  than  sixteen  (16)  inches  nor  more  than 
twenty-four  (24)  inches. 

19.  SIZE  OF  SECTIONS.     The  curb  and  gutter  shall  be  divided  into 
sections  not  less  than    five  (5)  nor  more  than  eight  (8)  feet  long  by 
some  method  which  will  insure  the  complete  separation  of  the  sections. 


Concrete     Pavements,     Sidewalks,     Curb    and    Git  tier 


i-       l*:f>  AA^&Ail          -«--    ^"  "'A*'" 4 1?*£.4~*. 


Figure  94 — Standard  Curb  Section.  Figure  95— Standard  Curb  and  Gutter  Section. 

20.  SECTION  AT  STREET  CORNERS.     The  construction  of  the  com- 
bination curb   and   gutter  at  street  corners  shall  conform   with   that 
shown  in  Figure  3.    The  radius  of  the  curb  shall  not  be  less  than  six 
(6)  feet. 

21.  WIDTH  AND  LOCATION  OF  JOINTS.     A  one-half  (^2)  inch  expan- 
sion joint  shall  be  provided  at  least  once  in  every  one  hundred  and 
fifty  (150)  feet. 

22.  JOINT  FILLER.     The  expansion  joint  filler  shall  be  a  suitable, 
elastic,  waterproof  compound  that  will  not  become  soft  and  run  out  in 
hot  weather,  nor  hard  and  brittle  and  chip  out  in  cold  weather. 

23.  PROTECTION  OF  EDGES.     Unless  protected  by  metal,  the  upper 
edges  of  the  concrete  shall  be  rounded  to  a  radius  of  one-half  (J^)  inch. 

Measuring  and  Mixing 

24.  MEASURING.     The  method  of  measuring  the  materials  for  the 
concrete,  including  water,  shall  be  one  which  will  insure  separate  uni- 
form proportions  at  all  times.     A  sack  of  Portland  cement  (94  Ib.  net) 
shall  be  considered  one  (1)  cubic  foot. 

25.  MACHINE  MIXING.     WTien  the  conditions  will  permit,  a  machine 
mixer  of  a  type  which  insures  the  uniform  proportioning  of  the  materials 
throughout  the  mass,  shall  be  used.    The  ingredients  of  the  concrete  or 
mortar  shall  be  mixed  to  the  desired  consistency  and  the  mixing  shall 
continue  until   the  cement  is   uniformly  distributed   and   the  mass  is 
uniform  in  color  and  homogeneous. 

26.  HAND  MIXING.     When  it  is  necessary  to  mix  by  hand,  the  mater- 
ials shall  be  mixed  dry  on  a  watertight  platform  until  the  mixture  is  of 
uniform  color  and  the  required  amount  of  water  added,  and  the  mixing 
continued  until  the  mass  is  uniform  in  color  and  homogeneous. 

27.  RETEMPERING,  that  is  remixing  mortar  or  concrete  that  has  par- 
tially hardened  with  additional  water,  will  not  be  permitted. 

Two- Count  Curb  and  Curb  and  Gutter 
Btue 

28.  PROPORTIONS.     The  concrete  shall  be  mixed  in  the  proportion 
of  one  (1)    sack  Portland  cement,  two  and   one-half  (2^)  cu.  ft.  fine 
aggregate,  and  five  (5)  cu.  ft.  coarse  aggregate. 

29.  CONSISTENCY.     The    materials  shall  be   mixed  wet  enough   to 
produce  a  concrete  of  a  consistency  that  will  flush  readily  under  slight 


U nirersal    Portland    Cement    Co. 


tamping,  but  which  can  be  handled  without  causing  a  separation  of  the 
coarse  aggregate  from  the  mortar. 

30.  PLACING.     After  mixing,  the  concrete  shall  be  handled  rapidly 
and  the  successive  batches  deposited  in  continuous  operation  completing 
individual  sections.     Under  no  circumstances  shall  concrete  be  used 
that  has  partially  hardened.     The  gutter  forms  shall  be  filled  and  the 
concrete  struck  off  and  tamped  to  a  surface  the  thickness  of  the  wearing 
course  below  the  established  grade  of  the  gutter.     The  concrete  for  the 
curb  shall  be  placed  and  tamped  so  as  to  permit  of  the  application  of 
the  required  wearing  course  to  the  face  and  top  so  as  to  bring  the  work 
to  the  established  line  and  grade  of  the  curb.  The  work  shall  be  executed 
in  a  manner  which  will  insure  perfect  joints  between  abutting  sections. 
Workmen  shall  not  be  permitted  to  walk  on  freshly  laid  concrete,  and 
if  sand  or  dust  collects  on  the  base,  it  shall  be  carefully  removed  before 
the  wearing  course  is  applied. 

Wearing  Course 

31.  PROPORTIONS.     The  mortar  shall  be  mixed  in  the  manner  herein- 
before specified  in  the  proportion  of  one  (1)  sack  Portland  cement  and 
not  more  than  two  (2)  cubic  feet  of  fine  aggregate. 

32.  CONSISTENCY.      The    mortar    shall    be   of   a   consistency   that 
will  not  require  tamping  but  which  can  be  easily  spread  into  position. 

33.  THICKNESS.     The  wearing  course  of  the  gutter  and  top   and 
face  of  the  curb  shall  have  a  minimum  thickness  of  three-quarters  (^) 
of  an  inch. 

34.  PLACING.     The    wearing   course    shall    be   placed    immediately 
after  mixing,  and  in  no  case  shall  more  than  fifty  (50)  minutes  elapse 
between  the  time  the  concrete  for  the  base  is  mixed  and  the  time  the 
wearing  course  is  placed. 

35.  FINISHING.     After  the  wearing  course  has  been  brought  to  the 
established  line  and  grade,  it  shall  be  worked  with  a  wood  float  in  a 
manner  which  will  thoroughly  compact  it.     When  required,  the  surface 
shall  be  troweled  smooth,  but  excessive  working  with  a  steel  trowel 
shall  be  avoided.     The  section  markings  shall  be  made  in  the  wearing 
courses  directly  over  the  joints  in  the  base  with  a  tool  which  will  com- 
pletely separate  the  wearing  courses  of  adjacent  sections.     If  excessive 
moisture  occurs  on  the  surface,  it  must  be  taken  up  with  a  rag  or  mop, 
and  in  no  case  shall  dry  cement  or  a  mixture  of  dry  cement  and  sand 
be  used  to  absorb  this  moisture  or  to  hasten  the  hardening.    The  edge 
of  the  curb  on  the  street  side  and  the  intersection  of  the  curb  and  gutter 
shall  be  rounded  to  a  radius  of  about  one  and  one-half  (1^)  inches. 
All  other  edges  shall  be  rounded  to  a  radius  of  three-eights   (^)   inch 
unless  protected  by  metal. 

36.  COLORING.    If  artificial  coloring  is  used,  it  must  be  incorporated 
writh    the    entire    wearing    course    and    shall    be  mixed  dry  with  the 
cement  and  aggregate  until  the  mixture  is  of  uniform  color.    In  no 
case  shall    the  amount  of  coloring  used  exceed    five    (5)    percent    of 
the  weight  of  the  cement. 


( '  o  n  c  r  c  t  c    P  a  v  e  m  e  n  1  .v  ,    N  /  d  e  w  a  I  k  s  ,    Curb    and    Gutter 

One- Course  Curb  and  One- Course  Curb  and  Gutter 

The  general  requirements  of  the  specifications  covering  two-course 
work  will  apply  to  one-course  work,  with  the  following  exceptions: 

37.  PROPORTIONS.     The  concrete  shall  be  mixed  in  the  proportion 
of  one  (1)  sack  Portland  cement  and  not  more  than  two  (2)  cubic  feet 
of  fine  aggregate,  and  three  (3)  cubic  feet  of  coarse  aggregate  passing  a 
one  (1)  inch  ring. 

38.  PLACING  AND  FINISHING.     The  forms  shall  be  filled,  the  concrete 
struck  off  and  the  coarse  particles  forced  back  from  the  surface,  and  the 
work  finished  in  usual  way. 

Protection 

39.  TREATMENT.     As  soon  as  the  concrete  has  hardened  sufficiently 
to  prevent  being  pitted,  it  shall  be  sprinkled  with  clean  water  and  kept 
wet  for  at  least  four  (4)  days.    The  work  shall  not  be  opened  to  traffic 
until  the  engineer  so  directs. 

40.  TEMPERATURE  BELOW  35  °  F.     If  at  any  time  during  the  progress 
of  the  work,  the  temperature  is,  or  in  the  opinion  of  the  engineer  v  Ml 
within  twenty-four  (24)  hours  drop  to  thirty-five  (35)  degrees  Fahren- 
heit, the  water  and  aggregates  shall  be  heated  and  precautions  taken  to 
protect  the  work  from  freezing  for  at  least  five  (5)  days.     In  no  case 
shall  concrete  be  deposited  upon  a  frozen  sub-grade  or  sub-base. 


UNIVERSAL  PORTLAND  CEMENT  CO. 

—  Offices- 
Chicago  72  West  Adams  Street 
Pittsburgh     -  -     Frick  Building 
Minneapolis                     Security  Bank  Building 

Plants  at  Chicago  and  Pittsburgh  Annual  Output  48,000,000  Sacks 


UNIUUHU 

A     000036588     2 


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